No less than three times in Digimon Frontier: ending Vritramon's rampage, activating the second Ancient Spirit Evolution, and awakening near-death Kouichi (complete with spreading light effect in the later case).
Toward the end of Pokémon: The First Movie, Ash is turned to stone in the crossfire between Mewtwo and Mew. Sparkling Streams of Tears from all of the Pokémon distraught by this resurrects him. The dub explains this early on through a story told by the pier master Miranda to the Pokémon trainers gathered at the pier.
In a Kanto episode, we have The Power of Friendship variety. The tears made Koffing and Ekans realize their masters would love them whether they evolved or not—so they stopped being worried and evolved. Meowth suggested that their time to evolve just happened to be then.
In a Johto episode Ash and his group met a Cute Witch who needed to collect an Aipom's tear to finish a spell that would grant them the ability to understand Pokémon language. After chasing a wild Aipom around and making it cry with laughter, the witch performed the spell... and turned Ash into a Pikachu.
In Yu-Gi-Oh!, Anzu/Téa (as the Magician of Faith) cried in mourning for Jounouchi/Joey's sacrifice against Bakura and this activated her flip effect. As the Magician of Faith she can move one magic card from her player's graveyard to his hand.
To make a youth potion for himself, Happosai needs one more ingredient: the tears of a beast that is both male and female. The rest of the chapter involves him chasing Ranma around with onions and tear gas.
The Nanban Mirror is a magic mirror that can transport someone to a desired time (and place) and requires teardrops to activate it. They don't need to be emotional tears, though.
Usagi's tears at Mamoru's first death creates the ginzuishou. In the manga, it simply forms from her tears, while in the anime, they cause the rainbow crystals to form it instead.
In episode 170, Usagi wanted to fight Neherenia and help Mamo-Chan, but her friends told her it's a trap, and as the heartbroken Usagi cried, her tear landed on her heart shaped brooch which caused it to turn into an eternal brooch and Usagi herself became Eternal Sailor Moon.
In InuYasha the Movie: Affections Touching Across Time, Sango sheds tears when forced to fight the mind-controlled Kirara and one of the drops happens to fall just on the mind-controlling device, thus empowering Kirara to snap out of it.
Baki the Grappler was nearly killed by Lee Kaiou's poison. As he lay dying, Kozue hovered over him crying. As luck would have it, human tears are are the natural antidote to that poison; not only curing Baki, but giving him the strength to kick Lee's ass eight ways 'till Saturday.
Inverted in Puella Magi Madoka Magica. At the moment when Miki Sayaka finally loses it and becomes a witch, it is her tears that turn her Soul Gem into a Grief Seed.
Tekken: Blood Vengeance. Towards the end of the movie Ling Xiaoyu sheds a single tear on Alisa Bosconovitch's face after she's ripped apart by Kazuya Mishima and this restarts her circuits.
In Toriko, the legendary Mellow Cola is the tears of the Salamander Sphinx. The Mellow Cola's nutritional value is so high that Toriko and Zebra are instantly revitalized after they exhausted themselves fighting a Nitro.
In a twist on Norse Mythology (see below), Marvel Comics' The Mighty Thor (back when the title was still Journey Into Mystery) had Loki trapped forever in the form of a tree unless someone cried for him, but he was such a dick that not even his wife shed a single tear. After a few millenia of experimenting, he discovered that he could make his leaves fall off, and managed to get one to drop into somone's eye. The resulting tear freed him, and the Marvel Universe has never been the same since— among many other deeds, he was indirectly responsible for The Avengers getting together.
Duma, angel of silence, speaks at the Sandman's funeral. His speech is a manifest miracle that lets every listener know that their life is meaningful, among other things. The speech consists of a single tear.
In one issue of the Superman comic based on the 1990s animated series, Supergirl contracts an Argoian illness. One of the ingredient is Element X, a unknown element — while saying good-bye to Supergirl, Superman cries. It turns out Kryptonians tear contain Kryptonian salt.
One Hulk story (circa Hulk # 300) has the heroic monster stuck in what appears to be a typical Fairy Tale world: an evil ruler holds a princess (whose tears create flowers) hostage while his minions enslave the populace. Not only is Hulk completely helpless in this world (it is never explained why) but the princess realizes she can use her tears to create plant monsters... and uses them to massacre the bad guys.
Rapunzel's tear cures blindness in her prince charming.
In "The Snow Queen", Gerta's tears washed the ice/mirror shard out of Kai's eye; her kiss melted the lump of ice around/in his heart.
Cinderella's godmother appears when she's crying; the Grimms' version has her cry on a lifeless twig, and it magically grows into a living tree.
In The Feather of Finist the Falcon, we have tears as magical laundry detergent: the heroine cries over her lover's bloody shirt, and so gets the blood out of it.
The servant answered: "It is a shirt of Finist the Falcon, who in three days will wed my mistress, but it is so stained with blood that I can by no means make it clean." The girl thought, "It is a garment my beloved wore after he was so cruelly wounded by the knives in my window!" And taking it from the other's hands, she began to weep over it, so that the tears washed away every stain and the shirt was as white as snow.
The black serving-woman took the shirt back to the Tsar's daughter, who asked her how she had so easily cleansed it, and the woman answered that a beautiful maiden, alone on the sea sand, had wept over it till her tears had made it white. "This is, in truth, a remarkable thing," said the Tsar's daughter; "I would see this girl whose tears can wash away such stains."
Film - Animation
Disney seems to like this trope.
Belle brings back the Beast by weeping over him in Beauty and the Beast. (This comes from the source material. Technically it's her declaration of love that breaks the spell, but her tears are proof of that love just as much as her words.)
Bambi 2, the Great Prince sheds a manly tear for his injured son, who is quickly revived.
In Tangled, Rapunzel brings Flynn/Eugene back to life this way. Her magical hair was gone, but the magic was still inside of her.
In Frozen, Elsa's tears of grief melt the ice around Anna's body and revive her.
Felix the Cat: The Movie: When her kingdom is invaded by the Duke of Zill's forces, Princess Oriana tries to summon The Chosen One, but is captured before she can finish. However, one of her tears starts glowing and promptly finishes the job — activating the machine by entering several codes, including a voice command, then tracks down Felix and lures him back through the portal.
Near the end of Filmation version of Journey Back To Oz where all of Mombi's magic was dying with her and Oz turned back to normal when she was defeated and Dorothy and her friends rejoiced until she saw her friend Pumpkin Head dead because he was created by Mombi, he died along with Mombi and her magic, but Dorothy's tear dropped on Pumpkin Head's forehead and Dorothy's tear brought Pumpkin Head back to life.
In Fantasia 2000, at the end of the firebird sequence when the forest was burned by the firebird, the sprites tears fell on the ground and it made the grass grow and then the sprite did the rest of making the trees, grasses and the flowers grow with her magic and then disappears.
Shrek 2: The Fairy Godmother had business cards that would summon her if anyone shed tears on them. Fiona shed tears, and got her, complete with the musical number. When Puss stomped on Donkey's hoof to make him shed a tear, they got voicemail.
Parodied in Lilo & Stitch 2: Stitch has a Glitch. After they are too late to save Stitch from his malfunction and he shuts down, Lilo's tear brings him back to life. It's parodied by the fact that Pleakley asks Jumba for the scientific explanation. Jumba proudly states (as if he knew any other way to state things) that there is no possible scientific explanation, declares it a miracle, and celebrates.
How Frank recovers in Osmosis Jones. Justified, as Ozzy, who has the MacGuffin needed to help him, hitches a ride in one of Shane's tears.
Film - Live Action
The end of The Neverending Story II movie. Tears allow for 'wishing from the heart' instead of the mind and grant Bastion an extra wish.
Nutty Professor II: The Klumpshas Sherman's Love Interest for this movie (played by Janet Jackson) fix things with a tear. When Sherman needs to reabsorb the arrogant Buddy Love back into his body or otherwise lose his intelligence, and Buddy is breaking down into liquid Buddy reaches a fountain before drying up leaving Sherman suck without his intelligence. Till Jackson's character's single tear drops through Buddy's remains and carrying them into the fountain allowing Sherman to get his smarts by drinking the fountain water.
In the film Fat Albert, the cartoon characters are able to enter the real world when the magic tear hits the remote control
in Osmosis Jones, When Frank is dying, his daughter cries and drops a tear in his mouth, and while it seems like the tears made a "miracle" in reviving Frank, it was actually Osmosis who went along the tear that made a difference.
Near the end of The Last Mimzy A tear falls on said Mimzy, a stuffed rabbit, who stores inside and brings it back to its creator in the future. This allows said creator to fix the Bad Future.
Downplayed in Takashi Miike's 'The Great Yokai War': The Hero was forced to kill a Yokai-friend that had been transformed into a monster. His tears restore its true form in its dying moment, but do not heal it. The Yokai-friend recovers by the end of the film.
In Pirates of the Caribbean: On Stranger Tides, mermaids' tears are a necessary ingredient to mix with the water of the Fountain of Youth.
The New Jedi Order. The alien Jedi Vergere's tears are naturally complex organic compounds which she can modify further with the Force. They can heal, among many other things (she frequently uses them as a paralytic poison).
In the Xanth novel Yon Ill Wind, Demon X(A/N)^th (yes, his name is a mathematical formula) makes a complicated bet that can only be won by getting the first Xanth resident he meets to shed a tear for him. (If he loses the bet, Xanth itself will be destroyed — or lose its magic, which is as close as makes no difference.) Unfortunately, said resident turns out to be Chlorine, who has already cried all the tears she has but one and would go blind if she shed that last one. She does, he wins, and Xanth is saved.
In Stephen Hunt's The Kingdom Beyond the Waves, a craybarian's tears are instrumental in conveying her immunity to poison to Amelia.
In Terry Pratchett's early novel The Carpet People, looking into a termagant's eyes turns people to stone, while its tears will turn them back again.
In The Velveteen Rabbit, the velveteen rabbit's real tear landed on the ground and it made the fairy appear.
In The Silmarillion, Lúthien Tinúviel's tears have healing properties. (Presumably as a result of her half-Maia ancestry.)
Inverted in Tiger Moon by Antonia Michaelis. It's Farhad's tears that turn Nittish to stone.
Live Action TV
Savaged in Six Feet Under when Billy and Brenda watch an animated version of the series of books they were obsessed with as children, and are dismayed at the Adaptation Decay they encounter.
Billy: A tear? He saves Isobel's life with a fucking tear?! Brenda: How does it happen in the book? Billy:Mouth to mouth resuscitation! Which makes sense!
Smallville: Chloe's healing powers were tear-activated the first time.
One episode of the original series of Star Trek had a race of Green Skinned Space Babes who had mind-controlling tears. Kirk made one cry and decided to wipe her tears away with his bare hand. Bad idea.
Much of season 7 of Buffy the Vampire Slayer revolves around a seal over the Hellmouth that's opened with by spilling blood on it. It's eventually revealed that to close it requires the tears of the person originally responsible for spilling the blood.
In the final episode of Power Rangers in Space, Andros cries at the sight of an apparently dead Astronema/ Karone. The tear trickles down his cheek and lands on Astronema's face, reviving her. It's widely believed to be a delayed reaction to Zordon's purification wave.
In an episode of Power Rangers Lost Galaxy, Karone comes across a warrior she fought andturned to stone back when she was Astronema, and she cries on him, restoring him. This must be a magical power for the residents of KO-35.
In Power Rangers S.P.D., a tear is responsible for allowing a nasty bad guy to escape... sorta. (He could travel through reflective surfaces. Naturally, nothing remotely shiny was allowed near his prison, but one Hannibal Lecture to Sky later, there's a Manly Tear...)
Lampshaded on an episode of Sabrina. Sabrina's mother was turned into a ball of wax. When she melted after Sabrina left her next to an iron she left on, Sabrina cried on her and she turned back. Her Aunts then run in and tell her that they finally found out that Sabrina can turn her mother back by melting her and mixing her with her tears, before noticing she figured it out herself.
Occurs in episode 4 of Kyoryu Sentai Zyuranger. In this instance, a child in the Continent of Despair who fears his mother to be dead begins to lose hope, and, due to the nature of this realm, turns into stone. His mother's tears, when they are reunited, return him to normal.
Also invoked in episode 4 of Hikonin Sentai Akibaranger, where Yumeria/AkibaYellow cries so that her tears can snap a supposedly brainwashed AkibaBlue out of her evil trance. There's just one problem: her helmet prevents her tears from working.
In the series finale of Legend of the Seeker, Richard is fatally stabbed by Kahlan, after fulfiling one of the prophecies and accidentally giving the Stone of Tears to the Keeper. Kahlan cries, and her tear falls on Richard, turning into another Stone of Tears. Power of Love, indeed. Despite the common usage of the trope, Richard isn't healed by the tear or the Stone; Cara revives him, and Zedd heals his eyesight.
Another doll line, PJ Sparkles, had a one-off pilot for an animated series. P.J. starts to die because she is hit with a hate beam by the movie's villains, but her new powers also cause her to die if she has no more love in her heart. The tears of a broken-down orphan declaring that he loves her revive her.
This trope was the origin story for the 1980s doll line Rose Petal Place. The resident family of a Victorian-style house moved away, and the little girl took one last stroll through its garden, weeping, before they left. Her tears changed some of the flowers into little maidens, and their houses, cars, etc. were similarly transformed toys and gardening implements. Each doll/accessory was thus marked with a "crystal" tear. Apparently, the magic was neutral, because it also transformed a spider into Nastina, Rose-Petal's Arch-Enemy. When Nastina killed her in the first of two animated TV specials by locking her in a room with almost no light (deadly for a flower woman), the tears of Rose-Petal's friends landed on her crystal, bringing her back to life. They found her because she managed to get a teensy bit of light shining on her crystal and the resultant glare was noticed by a passing butterfly; in the second special, Rose-Petal uses this glare to avoid being literally mowed down by Nastina.
In Final Fantasy VI, the petrified princess of the underground castle can shed a tear that upgrades the Magicite remains of her Esper suitor.
Used in Mario & Luigi: Partners in Time. The cure to the Shroob infection that devastated Mushroom Kingdom in the past was Baby Tears. Though it was somewhat subverted in that Professor E. Gadd whipped up a 'chemical equivalent' to do the job en masse.
In Metal Gear Solid 2, one of Fortune's tears brings Vamp back from a bullet to the head, but it's implied that contact with any water source can do this.
Inverted and also used in Legend of Mana. Anyone who cries for a Jumi (basically Elves) will turn to stone, but the Jumi's own tears have healing powers. Both of which actually happen at the end of the Jumi arc.
In Final Fantasy XI it is said that the goddess Altana created the Zilart, but once they were destroyed, she wept five tears down on the world that resulted in the creation of the five races.
In Sam & Max: Ice Station Santa, elf tears make plants grow.
In Free Realms the Druidess Queen Ayani goes one better. Her tears form rivers and lakes and where her tears touched the ground flowers and trees began to grow.
Three examples in The Legend of Zelda: Twilight Princess; the Tears of Light, which are used to give the Light Spirits back their powers, the Great Fairy tears Link can drink to heal him and increase his strength, and Midna using her magic tear to shatter the Mirror of Twilight before returning to her own world and separating both her and Link's world. That last one involves regular tears as well.
In Super Princess Peach, when you choose Peach to cry, her tears can make plants grow to climb on, make her run faster, make water wheels go around and also defeat bad guys.
In Brütal Legend, the Sea of Black Tears is a source of power, and evil.
Deconstructed by Kanon. Mai Kawasumi cures her mother with her tears, and people eventually learn that her tears have the ability to rejuvenate anything, even after it has died. Unfortunately, since she's living in a modern setting, she gets swept up in a media circus that publicizes her powers, is persecuted by the people around her for being different, and is eventually forced to leave her town.
The Powerpuff Girls are brought back (from death?) by tears in "The Rowdyruff Boys" and "Knock It Off." They're also brought back from a berserker rage by Mojo Jojo's tears, after they give him an especially brutal beating for stealing the candy that they've become addicted to. What have they done?
In Futurama, the solution to Fry drinking an emperor, an alien made up of liquid, is to have Fry cry out him out. After he has trouble making himself cry, the rest of the crew pretend Leela is being killed because of his actions. Until Leela arrives alive ruining this plan, but she beats up Fry to make him weep in pain. Hilarity Ensues, because while Leela, and later the rest of the crew, are beating the crap out of him, he's still thanking them profusely. They continue beating on him after the Emperor has recovered. Even the Emperor himself thanks him for crying him out before beating him with a chair.
The Sponge Bob Square Pants Movie: SpongeBob and Patrick are captured by a diver who makes souvenirs out of dried-up sealife and are placed under a heat lamp. As they await their fate, they each shed one tear that join to form a heart. That one heart-shaped tear then drips down the power cord into the outlet, causing it to short and activate the sprinkler, which revives our heroes and all the other creatures as well.
In the original series, SpongeBob loses his pineapple home after nematodes drink it dry, leaving a little "pebble" behind. Near the end of the episode, he plants it in the ground, and a single tear falls on it, restoring it back to normal (on top of Squidward).
In the Grand Prix-winning Rene Laloux short Les Escargots, A down-on-his-luck farmer discovers that crying on his lettuces makes them grow large and healthy. Unforunately, it has the side effect of attracting snails the size of Mack trucks which go on a rampage in the nearby town once they've picked his field clean...
South Park: Parodied: a statue of the Virgin Mary is crying blood from her ass, and Randy Marsh thinks it'll cure his alcoholism.
In The Fairly Oddparents special Fairy Idol, when Norm the Genie crosses the Moral Event Horizon by brutally crushing Cosmo and Wanda with a giant wrecking ball, Timmy ends up in tears, depressed at how crappily he had treated him earlier in the special, prompting them, in their full body casts, to float up to the air, as if to demonstrate a straight example of this trope, only to end up becoming a subversion when they disintegrate into fairy dust. Even THEN, tough, they reveal themselves to have already gotten better by themselves, thus double subverting this trope.
In Bartok the Magnificent, the witch Baba Yaga told Bartok the Bat that the final ingredient she wanted for her potion was something from himself. When Bartok pulled out his own hair thinking that was what she wanted, Baba laughed at him and Bartok angrily yelled at Baba for that and Bartok said that everyone hates her. Then Baba started crying and after Bartok felt bad for her, he started crying and Baba got the final ingredient she wanted: tears which came from Bartok's heart. She put Bartok's tear in her cauldron and completed a potion to transform someone into becoming on the outside what they are on the inside. It turns the villain into a dragon.
In She-Ra: Princess of Power episodde ""My Friend, The Enemy". Hordak was disappearing to death from eating the doomberry pie Skeletor gave him, but Hordak was saved by She-Ra's tears.
In Once Upon a Forest, Michelle is still unconscious even after she receives the medicine; it is only Cornelius' tears which cause her to awaken.
In the pilot episode of The Dreamstone, Amberley has been turned to stone by Zordrak, and a single tear from Rufus is enough to reverse the spell.
In Season 3 of the Winx Club, Stella had been turned into a monster and her friends have to get to the mirror of truth to break the spell. It didn't break the spell on its own but then Stella's tears touched the mirror and it shattered into a lake and after she got a gift from Brandon, Stella was touched and her other tear landed on the lake and changed her back into a human. Love changed her back and it was expressed through her tears.
In the end of final Peter Pan & the Pirates episode: Never land was disappearing and everybody was falling because Peter Pan grew up to an old man and he didn't believe in never land and forgotten about Tinker Bell. Tinker Bell convinced Peter as an old man to believe in never land and become young again and after Peter remembered Wendy's laugh and Tink herself and realized he made a mistake about growing up. Tink's tear landed on Peter and Tink's tear changed him back into a young boy and everything turned back to normal.
No Heart creates a raincloud that washes away one's color. When the Care Bears and one of the humans confronted him, the rain wound up hitting Wish Bear. The human boy she was protecting cried on her, and his tear hit her tummy symbol, undoing the effects and allowing her to break the impasse.
Hugs and Tugs fake having a chicken-pox like disease. When they clean themselves up and try telling Grams Bear, she sees them and think that the disease is in its second stage, at which point only a teardrop from the Big Bad can provide the cure.
One episode of Dungeons & Dragons has Sheila break the spell on a cursed king when she cried a Single Tear of gratitude over him for helping to save her brother.
Ren and Stimpy "The Littlest Giant" has Stimpy the "Little Giant" leaving the giant country in exile and sob all over and filling farmer Ren's dried up well with his tears. They both become friends in result.
The Amazing World of Gumball: A single tear from Darwin was enough to revive a pet turtle. But since this particular turtle was a nigh-unstoppable terror driven by an obsessive need to bite, Gumball has a different theory: It feeds on misery.
Human tears contain Lactoferrin, a protein that has been found to fight various infections.