Let's go through them, shall we:
Zeus - Blessed Philemon and Baucis as a reward for their good hospitality, transforming their home into a grand temple and granted them a wish. Their wish was to die at the same time, so that neither would have to mourn the death of the other. Zeus turned them into trees upon their deaths, so they could forever stand entwined with each other.
- Supported his son Herakles throughout his labours, and granted him apotheosis immediately upon his death.
- Had Hypnos and Thanatos spirit the body of his son Sarpedon off of the Trojan battlefield, so that he could be given a proper burial.
- Releases the elder Cyclopes and the Hekatonkheires from their imprisonment.
- Lets Hecate retain her domains over the sky, sea, and underworld after the Titanomachy, and grants her more honors besides.
- Restored Pelops to life (a very rare breach of the protocol around death) after his father Tantalus killed him and served him to the gods as food. Zeus also ordered Hephaestus to make an ivory prosthetic for Pelops, because Demeter absentmindedly ate his shoulder.
- Sends his eagles to retrieve water from the Styx to help Psyche accomplish her impossible tasks and win Eros back. When Psyche’s final task resulted in her death, Zeus granted her apotheosis and approved her marraige to Eros.
- Grants Eos and Selene’s requests to give their respective mortal husbands immortality. (This goes better for Selene than it does for Eos.)
- Grants his daughter Artemis’ request to remain a virgin, and never be forced into marraige.
- Grants his son Polydeuces’ request to not be parted from his brother Castor when Castor dies. As a compromise, he splits Polydeuces’ immortality between them, allowing them to spend half their time on Olympus and the other half in the Underworld. They become the constellation Gemini.
- Eventually granted apotheosis to Asklepios, at the request of Apollo.
- Blessed Cadmus and Harmonia with “success in all things,” and gave Thetis a pair of ankle-wings, at their respective weddings.
- In some sources, he eventually forgave his father Kronos and freed him from Tartarus, appointing him the king of Elysium.
- Adopted Pegasus after having Bellerophon cast to earth, and appointed Pegasus the bearer of his thunderbolts.
- Placed many of his children in the sky as constellations, to commemorate their deeds for all time. (Examples include Perseus, Herakles, and the Dioskouroi.)
Hera - Supported Jason throughout his adventure.
- Supported the Achaians on the battlefield during the Trojan War, even seducing Zeus and putting him to sleep so that he couldn’t interfere.
- Bestowed wisdom and beauty upon the Pandareides.
- Gave a cloak to Peleus as a wedding gift, and gave Cadmus and Harmonia a throne.
- Sent Hephaestus to rescue Achilles from the River Scamander.
Poseidon - Aided the Achaians during the Trojan War.
- Helped save Achilles from the River Scamander.
- When Ino threw herself and her son Melicertes into the sea in a fit of madness, he granted them apotheosis. They became the friendly sea gods Leukothea and Palaimon.
- Gave magical horses to his lover, Pelops, to Heracles, to Peleus, and to the Dioskouroi.
- He also gave the Dioskouri the ability to aid shipwrecked sailors. (They were associated with the phenomenon later known as “St. Elmo’s fire.”)
- Turned Caeneus into a man, and gave him impenetrable skin. (The way Ovid tells it, Poseidon raped Caenis and then granted her a wish, and she wished to turn into a man so she wouldn’t have to go through that ever again. In that context, this isn’t a real example of kindness or favor on Poseidon’s part. However, earlier tellings leave it more ambiguous. YMMV)
Demeter - Taught humans agriculture so that they would survive the winters caused by her grief over he daughter.
- Rewarded King Celeus for his hospitality by nursing his son Demophoon, giving him a godlike appearance and exceptionally long life. (She would have made him immortal, but she was interrupted.)
- Gave a man called Phytalus the first fig tree, also as a reward for hospitality.
- Placed her son Philomenus in the sky as a constellation (Bootes), to honor him for having invented the plough.
- Took pity on Plemnaios, a king whose children all died immediately after being born, by raising his last son herself.
- Raised a son of Apollo, Trophonios, alongside her daughter. He eventually apotheosized and became an oracular daimon after his death.
- Granted apotheosis to Triptolemos, a hero who helped Demeter teach humans agriculture and became one of the first priests of the Eleusinian Mysteries. She also gave him a dragon-drawn chariot so he could spread her gift more easily.
Hestia - There aren’t that many specific myths about Hestia, but she’s just generally nice and was very important in a religious context as the goddess of the hearth, domestic life, and burnt offerings.
Ares - Inspired the Amazon warriors with their fighting spirit; many of the Amazon queens were his daughters, such as Hippolyta, to whom he gave his own belt, and Penthesileia, to whom he gave armor and weapons and other support in the Trojan War.
- Supported various mythological war campaigns; fought for the Trojans in the Trojan War, until Diomedes wounded him.
- Gave a herd of man-eating mares to a different Diomedes, one of his sons. (Herakles had to steal them for one of his labours.)
- Gave armor, weapons, and magical horses to Oinomaos (who still lost to Pelops, because of sabotage).
- Blessed his son Nisus with a lock of purple hair that would ensure his kingship.
- Prevented Hermes from harming his monstrous half-bear grandsons, Agrios and Oreios. (Zeus told Hermes to punish them for existing in any way he chose, so he decided to cut their hands and feet off. Ares convinced him to turn them into birds instead.) They were changed into an owl and a vulture, birds sacred to Ares (and considered to be bad omens by the Greeks). Their nurse was changed into a woodpecker, but prayed not to be an evil bird. Hermes and Ares heard her, and blessed her as a bird of good omen.
- Gave Aeetes a cuirass and the dragon that guards the Golden Fleece, and also gave him fiery bulls that he can use to plough a field with the dragon’s teeth and cause warriors to sprout up (just like Cadmus).
- Danced at his daughter Harmonia’s wedding, and gave her and her husband a spear as a wedding gift.
- Eventually delivers Cadmus and Harmonia from their punishment (being turned into snakes), and brings them both to Elysium.
Hephaestus - Fashioned weapons, armor, jewelry, and many other beautiful things for gods and mortals alike, including the armor of Herakles, Achilles, and Aeneas.
- Alongside Athena, gave humans most kinds of technology, so they could stop living in caves and build themselves a civilization.
- Purified Pelops of miasma after Pelops murdered Myrtilos, Oinomaos’ charioteer.
- Gave Orion a guide, Kedalion, when he [Orion] was blinded. (Orion deserved to be blinded, though.)
- During the Trojan War he saved the son of one of his priests, Dares, simply so that the old man wouldn’t have lost both his children.
- Sent his twin sons, the Kabeiroi, to join Dionysus’ Indian campaign, and rescued them from death multiple times.
- Helped Achilles escape from the river Scamander by drying up some of its water with flames.
Aphrodite - Gave Hippomenes the golden apples that he needed to win the hand of Atalanta.
- Granted Pygmalion’s wish for his statue of a perfect woman, Galatea, to become a real woman.
- Gave jewelry to Harmonia and Thetis as wedding presents.
- In some tellings, it was Aphrodite who asked Poseidon to turn Ino and Melicertes into gods.
- Bestowed beauty upon Metiokhe and Menippe (Orion’s daughters).
- Raised the Pandareides after their parents died.
- Saved Butes, an Argonaut, from becoming a victim of the Sirens after he jumped into the sea upon hearing their singing.
- Granted her intersex child Hermaphroditos’ request that the pool of Salmakis have the power to make anyone who bathes in it a hermaphrodite.
- Bestowed many gifts upon Paris for giving her the Apple of Discord, and helped him to carry off Helen. Helps reconcile Helen and Menelaus once the war is over.
- Supports her son Aeneas throughout his adventures, and convinces Zeus to grant him apotheosis. Later became the patroness of Rome.
Apollo - Taught mortals music, medicine, archery, and divination.
- Purified Orestes of miasma for the murder of his mother Klytemnestra, and acted as his defense attorney during the ensuing trial.
- Answers whatever questions mortals bring him through the Delphic oracle, even if they don’t like the answers. This includes telling them how to get rid of disease and miasma.
- Doted upon King Admetus while enslaved to him for a year; he helped Admetus win the princess Alcestis, and caused all of the animals he tended to bear twins.
- Showered gifts upon another of his lovers, Branchus, giving him a crown and magical staff, as well as the gift of prophecy.
- Aided the Trojans during the war; guided the arrow that Paris shot to kill Achilles.
- Gave Herakles his bow and arrows.
- Blessed Nestor with exceptionally long life.
- Convinced his father Zeus to spare Periphas, when Periphas’ subjects began to worship him as if he were Zeus. Zeus wanted to smite him, but relented, and instead turned him into his sacred eagle.
- Sang and played the lyre at Cadmus and Harmonia’s wedding, and Peleus and Thetis’ wedding.
- Supported Theseus in his quest to slay the Minotaur. (Theseus’ offerings of gratitude are the mythic basis for the Pyanepsia festival.)
- Protected his lover Rhoeo when she was thrown into a chest by her father (who believed that her lover was a man). She washed up safely on Delos, where Apollo received her and raised their son. He also saved Rhoeo’s two sisters from taking their lives over an unrelated incident.
- Alongside Hermes, turned Daedalion into a hawk to prevent him from taking his own life when his daughter was shot by Artemis.
- When his devotee Eumelus accidentally killed his friend Botres over a dispute, and immediately regretted it, Apollo turned Botres into a bird (a bee-eater).
- Helped Euippus rebuild the walls of Megara.
- Blessed multiple mortals with the gift of prophecy, including Melampus, Branchus, Phineas, Andros, Carnus, Tenerus, and of course the various Delphic oracles (and Cassandra, though his later curse on her sort of negates that).
- Collected what was left of Zagreus’ body, and buried it at Delphi. Has the epithet Dionysodotes, “Bestower of Dionysus,” for this reason.
Artemis - In some tellings, she rescues Iphigeneia instead of letting her die, and puts an animal in her place; in one of these, Iphigeneia is granted apotheosis, and becomes the goddess Hecate.
- Blessed Daphne (a different one) with the ability to always shoot straight.
- Persuaded Asklepios to bring her devotee Hippolytus back to life, giving Hippolytus’ tragic story a much-deserved happily ever after.
- Placed Orion in the sky as a constellation after he was killed by the scorpion. (Tellings differ; in some, Artemis killed him herself.)
- Gave Prokris a javelin that would always hit its target and a hunting dog that would always catch its prey. Artemis initially rejected Prokris’ company because she was not a virgin, but when Prokris explained that her husband was cheating on her with Eos, Artemis was moved and gave her the gifts to win her husband back.
- Bestowed apotheosis upon Britomartis, saving her from men who wanted to rape her. (Britomartis was a local Cretan goddess with whom Artemis was syncretized.)
- Rescues Erigone from being killed by her half-brother, Orestes.
- Gave hunting dogs to Kyrene.
- Granted apotheosis to Phylonoe/Polyboea (a sister of Helen, Klytemnestra, and the Dioskouroi).
- Granted apotheosis to Eukleia, one of Herakles’ daughters, who died a virgin, adopting her as one of the nymphs in her retinue.
- Gifted the Pandareides with tall stature.
- Saved Arethusa from being raped by the river-god Alpheios by turning her into a Naiad, resulting in a sacred spring.
- Saved Pholoe by being raped by Pan, also by turning her into a pool.
- Relieved the sisters of Meleagros from their grief over his death by changing them into guinea-fowl.
- Calmed her brother Apollo during his fight with Heracles over the Delphic tripod.
- In one version of Kallisto’s story, Artemis encounters her in bear form and shoots her, not realizing who she is. When she realized that she killed her friend, she placed Kallisto in the stars as Ursa Major.
- Saved Klinis, Artemikhe and Ortygios from being devoured by man-eating donkeys (a curse from Apollo, who was very displeased at the insufficient sacrifice).
Athena - Invented the loom, the plough (in some accounts), the bridle, the chariot, and the double-flute. She gave many of these inventions to humans and taught them how to use them. She’s especially known for having taught women how to make handicrafts and textiles.
- Taught weaving to Metiokhe and Menippe, Eurynome, the Koronides, and Arachne (though Arachne later denied that she’d ever learned from Athena).
- Lent her shield to Perseus; guided and protected him throughout his attempt to kill Medusa.
- Gave Bellerophon the golden bridle, and taught him how to tame Pegasus with it.
- Guided and protected Odysseus throughout his journey home to Ithaka, and also was the OG Mentor to his son Telemachus.
- Fought for the Achaians in the Trojan War, and gifted Diomedes with the ability to wound gods.
- Helped save Achilles from the River Scamander.
- Inspired Odysseus with the idea for the Trojan Horse, and taught Epeios how to build it.
- Prevented Achilles from murdering Agamemnon in a fit of rage at the beginning of the Iliad.
- Gave Herakles a cloak, and helped him with several of his labours. She supported him in the battle with the Hydra, brought him noisemakers from Hephaestus to scare the Stymphalian Birds, returned the Apples of the Hesperides to their garden, and helped guide him out of the Underworld. Also supported him in several other wars, and calmed him down when he fought with Apollo over the Delphic tripod. Personally brought him to Olympus upon his apotheosis.
- Gave a flute to Peleus as a wedding present.
- Warned Theseus to dodge a branch that the centaur Demeleon threw at him, so that it narrowly missed. (I’d expect Athena to help her own city’s most celebrated hero more, but nope.)
- Turned a princess into a crow to prevent Poseidon from raping her.
- Took pity on Nyctimene, a girl who hid herself in shame because she was raped by her own father. Athena turned Nyctimene into an owl and adopted her.
- Raised Erikhthonios as her own son. He later became the first King of Athens.
- Gave Asklepios the magical blood of Medusa to use as a medicinal reagent.
- Personally instructed Daedalus, the master craftsman. Daedalus once tried to kill one of his apprentices, his own nephew Perdix, out of envy for the boy’s skill; instead of letting Perdix die, Athena turned him into a partridge.
- Taught shipbuilding to Argos (the builder of the Argo), and to Danaeus, who built the first ship. Danaeus’ fifty daughters later murdered their husbands, and Athena purified them of miasma.
- Gave Tiresias the gift of prophecy. She blinded him because he caught her naked, but (in stark contrast to Artemis), immediately felt bad about it and compensated by making him one of the most gifted seers in Ancient Greece.
- Instructed Cadmus and Aeetes in how to sew the dragon’s teeth to grow a magical army.
- While Athena did become very angry at Arachne for mocking her, she didn’t turn Arachne into a spider to punish her, but to prevent her from taking her own life after the contest. She also allowed Arachne to retain her ability to weave. Whether this is an act of mercy on Athena’s part or not, YMMV.
Hermes - Blessed Philemon and Baucis alongside Zeus.
- Granted Perseus the use of his winged sandals and other magical items.
- Gave Odysseus the moly that would allow him to resist Circe’s spells. (Odysseus’ famous guile is also attributed to him being a grandson of Hermes.)
- Gave Herakles a sword, and guided him into the Underworld for his twelfth labour.
- Hid the baby Dionysus from Hera (in Nonnus’ telling, he even assumed the guise of the progenitor god Phanes to throw her off), and spirited him away to be raised by the nymphs of Nysa and/or Ino.
- Gave the cloud-nymph Nephele a golden ram to be sacrificed in place of her children. (The ram’s skin is the Golden Fleece.)
- Gave magical horses to the Dioskouroi.
- Guided the Trojan King Priam through the Achaian camp when he came to get Hector’s body back.
- Guided the shade of Protesilaos up from Hades so that his wife Laodameia could say goodbye to him. (It… didn’t really help.)
- Granted his son Aithalides a memory so powerful that he could remember previous incarnations.
- Made his son Autolykos a master thief, and even gave him the power to magically transform the animals he stole in order to to disguise them.
- In one telling of Kallisto’s story, Artemis shot her, and Hermes saved the baby Arkas from her womb.
- Saved the baby Asklepios from being burned on his mother’s funeral pyre.
- Brought the baby Aristaios up to Olympus to be raised by the Horae.
- Turned Daedalion into a hawk (alongside Apollo) to prevent him from taking his own life when his daughter was shot by Artemis.
- Taught Amphion how to play the lyre with supernatural skill.
- Honored his son Myrtilos’ dying wish for Pelops’ entire family line to be cursed. (The House of Atreus is probably the most cursed family in all of Greek mythology, so… don’t mess with Hermes’ sons.) Hermes also put Myrtilos in the sky as a constellation.
- Gave Cadmus and Harmonia a lyre or a scepter as their wedding present.
- Allegedly granted Aesop’s prayer for wisdom and eloquence, inspiring him to write his fables.
Dionysus - Traveled around the whole eastern Mediterranean, teaching humans how to make wine, which is explicitly described as being a reprieve from daily suffering — essentially, he gave us liquid joy.
- Brought viticulture to Attica by teaching it to Ikarios. Unfortunately, it went badly for Ikarios and his daughter, but after that whole mess, Dionysus placed them in the sky as the constellation Virgo.
- Rescued Ariadne from being stranded on Naxos (tellings differ) and gave her a beautiful crown with seven jewels as a wedding gift. When Ariadne died, he granted her apotheosis as his wife, and placed the crown in the stars as the constellation Corona Borealis.
- Descended all the way into Hades to rescue his mother (and sometimes also his wife, Ariadne), and bring her to Olympus. He granted Semele apotheosis, and she became the goddess Thyone.
- Taught his mysteries to Orpheus, who began the Orphic Mysteries. In some tellings, he also did not approve of Orpheus’ death, and avenged him by turning the offending Maenads into trees.
- Found Hephaestus after he had been thrown off Olympus, with both his legs permanently damaged. Dionysus helped him onto the back of a donkey and brought him back to Olympus.
- Spared Akoetes the fate of the other Tyrrhenian Pirates, because Akoetes was the only pirate who caught on that their captive prince was actually a god. He instead became a favored priest of Dionysus’ cult. (Some tellings also present Dionysus turning the pirates into dolphins as an act of mercy — he could have let them drown, but didn’t.)
- Granted Midas a wish after Midas was kind to Dionysus’ mentor, Silenus. After it turned out to be a disaster (the Golden Touch was genuinely meant to be a gift, not a curse; Midas is just stupid), he took it back with no fuss.
- Blessed several Greek islands with the most abundant vineyards in Greece, and then gave them to his sons.
- Blessed the Oenotrophi (three princesses) with the ability to turn anything they touch into olive oil, wine, and grain, and/or to call it up from the earth. When Agamemnon later kidnapped them, Dionysus rescued them by turning them into doves.
- Some tellings have Dionysus be the one who turned Ino and Melicertes into sea gods.
- Placed his lover Ampelos in the sky as the constellation Bootes after his death.
- Placed two donkeys in the sky as the constellation Cancer, to honor them after they carried him across a swamp while he was mad.
- Turned one of his devotees, Dirke, into a sacred spring when she was killed by Amphion and Zethos.
- Blessed his nursemaids by having Medea make them young again, and placed them in the sky as the Hyades star cluster in the constellation Taurus.
- Gave a centaur called Pholos a jar of fine wine, with the strict instruction that he should only open it to share it with Herakles.
Hades - Appreciated Orpheus’ music so much that he granted him a fair shot at winning Eurydice back. Unfortunately, it didn’t work out.
- Allowed Herakles to borrow Cerberus, with the condition that Cerberus remain unharmed. Also allowed him to take Theseus (but not Pirithous) out of the Underworld.
- Lent his Helm of Darkness to Perseus in some tellings.
Persephone - Gave Psyche some of her beauty in a box, to help accomplish one of her tasks.
- Was moved to tears by Orpheus’ music, and helped convince Hades to let Eurydice go.
- Sent Alcestis back to life, after she died in Admetus’ place.
- Took pity on Sisyphus after he arrived in the Underworld without proper funerary rites, and sent him back to life so that he could be buried properly. (It was a trick; Sisyphus intended to take advantage of her compassion to live out the rest of his natural life. She was probably less than sympathetic when he died for good.)
Many of the stories of the gods’ favor aren’t as well-known as the instances of their wrath, and many also don’t translate very well. (Metamorphosis is just as often a blessing as a punishment, and which one it is depends a lot on the context of the story.) But still — there’s lots of instances of the gods helping out mortals, and even the more famous ones (like Athena and Hermes’ aiding of heroes) tend to get sidelined by modern commentators. These are also all strictly mythological instances; in the religious context, gods provide smaller blessings for mortals every day by making the rains fall, the crops grow, keeping cities safe, aiding in healing, protecting travelers, granting inspiration, and so on.