The complete opposite of Sealed Evil in a Can. This entity is usually kind and gentle, and usually (if not always) rewards the one who releases it, if it can. In other cases, the wandering band of travelers are desperately trying to evade capture or being killed by the forces of darkness. They stumble upon the entity and, thanks to a can-opener (which can range from a trinket to a sacrifice), the only thing that can stop the great evil awakens, and prepares to open a can... of whoop-ass. Sometimes it's revealed that there is a baddie in there with them and they were the Barrier Maiden or the ever-fighting guard keeping them in (Sealed Evil in a Duel). In these cases their release also releases the Sealed Evil in a Can. Oops.
Comes in two flavors:
Type 1: Sealed by allies. Similar to Sealed Badass in a Can. There was something in the future they would be needed to combat, so to make sure they would be ready, the Good let themselves be sealed. If the future threat was simply "bad guy I need to beat up," it's probably a case of Sealed Badass in a Can instead.
Type 2: Sealed by enemies. A straight inversion of Sealed Evil in a Can. There was a great foe that no one could defeat, so they sealed him away instead. Only difference is that the foe is the good guy, and the sealers evil.
The original sealing away of Alexiel in Angel Sanctuary is a borderline example of this. True, she was captured trying to bring down Heaven's ruling class. On the other hand, the angels and demons vary so much between moralities that it's hard to say whether she's good or evil.
C.C. from Code Geass is almost literally Sealed Good In A Can, since she begins the series locked inside a mechanical capsule that supposedly contains poison gas.
The protagonist of the Geass game Lost Colorsput himself into a coma within a Geass ruin following the death of his friends and family, making him a rare case of self-sealing.
An early chapter of Crimson Spell features an example of this trope in the form of the magical spirit-creature Lizregbel, released by Vald and Havi and promptly renamed "Ruruka" after Val's little brother's pet bunny.
In Digimon Xros Wars, it turns out the DigiMemories are actually a group of ancient, heroic Digimon that protected the Digital World. They were ultimately sealed in there in a failed attempt to stop the break up of the Digital World.
Goldramon has two dragons sealed in his bracers: Amon of the Crimson Blaze, who administers destruction, and Umon of the Blue Thunder, who administers creation.
Elder Kai from Dragon Ball Z was was sealed in the Z Sword a few billion years ago and when he comes out he provides lots of help in the effort against Buu.
In the Piccolo Jr. Saga, Kami attempted to seal Piccolo (the then Big Bad) in a bottle with the Evil Containment Wave. Piccolo bounced it back at Kami, sealing him until Goku beat Piccolo and freed him.
Gungrave: Before his death, Brandon Heat left a letter for Big Daddy, stating that in the event of his (Brandon's) death, and if Harry and the Millenion goes down the wrong path, Brandon would allow his body to undergo necrolization and become a Deadman. His last request was to remain locked away in the doctor's confinement chamber, in a state of hibernation, until the time he needs to be summoned. Brandon (better known as "Grave"), "sleeps" for thirteen years until Mika (Big Daddy's daughter) awakens/releases him because she was told to seek his protection.
In Mamotte Shugogetten, Shaorin and other spirits were imprisoned in objects for several hundred years at a time, only coming out to serve a master who was pure of heart. Unlike with most cases, exactly why this is done and who does it are a mystery. (Especially since none of them seem to have done anything to deserve it.)
In the end of the first arc of Mermaid Melody Pichi Pichi Pitch, the recently reformed Gackto, Sara and the Dark Lovers are sealed under the ocean forever for their crimes. Although she's not going to go and turn on Aqua Regina for it, Lucia mourns them as if they were dead and is surprised to see them astral project in the Pure arc.
The Monster Rancher anime had both Sealed Good and Sealed Evil. The goal of the protagonists became to revive the Phoenix before Mu could fully revive his original body.
Oddly enough, Naruto himself is the subject of both this and Sealed Evil in a Can. When the 4th Hokage, his father, sealed the Nine-Tailed Fox into Naruto, he sealed his own soul into Naruto as well. His soul serves as a failsafe to prevent the seal on the Fox from breaking. Not to mention that if it were possible him to get it out (it isn't), it would double as Sealed Badass in a Can.
The BW arc of Pokémon Special ends with Black getting sealed into the Light Stone in front of a horrified White.
Prince Mythos from Princess Tutu does not literally seal himself, but shatters his heart and seals the pieces in order to seal the Monster Raven. As Princess Tutu returns his heart shards and emotions, the seal on the Raven gets correspondingly weaker.
In Rave Master Elie/Resha is one of these. She was sealed away to combat the threat that would arise in fifty years time.
This is what Mikael and Silky from Tenshi Ni Narumon did to themselves - they sealed their fallen halos, in a box (well, more like three boxes) in Mikael's case and in a drawer in Silky's case. Given that a fallen halo means losing potentiality of becoming an angel (losing any goodness) and is basically an expression of self-hatred, it's no wonder why they both turned into such psychos at the end.
Mashiro in Tayutama chose to be sealed along with the Tayutai knowing that if they're freed she'll be freed along with them and can seal them again. She would much rather work with them and get them to get along with humans than fight them. She will fight if necessary however, which is what she does almost immediately upon being released. She then lectures the ones she defeats about how they need to be nice.
Nuts from Yes! Precure 5 was trapped inside the Dream Collet after he let a Kowainaa into his kingdom by mistake.
Yu-Gi-Oh!: Pharaoh Atem sealed himself along with the Big Bad so he would be around to defeat the Big Bad again when he was inevitably unsealed in the future.
Zombie Fairy has the zombie fairy, bound in a coffin. This is also a case of sealed evil in a can, as she is under a curse that causes her to go into berserker rages.
Camelot 3000 is all about the Sealed Good of King Arthur being revived from a millennia-long hibernation to battle alien invaders.
Captain America, frozen in 1944 and thawed out again in... well, whenever the current continuity says (roughly 12 years from whenever you're reading).
Marvel Comics' Tiamut the Dreaming Celestial was the only member of his race that objected to their genocidal policies and was punished for it.
If newspaper comics count, then there's the Ekert from Non Sequitur.
As per the 2010 Spiderman annual, Captain America was thawed out five years ago from that date.
And also Primus, god of the Transformers, who sealed himself away at the core of Cybertron itself in order to also seal off his opposite number, Unicron. He was also present in the Unicron Trilogy, but he was created in the comics.
Though it's worth noting that Primus' sealing himself off less directly sealed Unicron and more caused Unicron to pick up a moon-sized Idiot Ball and do it himself just to prove he could.
Well, whatever works. They never said Primus wasn't a sneaky bastard. They just said he wants the universe to keep on existing.
In Diaries of a Madman, the elementals were sealed in one by Discord, and one of Navarone's goals is to free them.
Arceus, the creator of the Pokemon world, starts out as one in A New World, A New Way. Then he gets out, and kicks off the story's plot.
A New Chance Series: The Father Latios, who sacrificed himself to save Altomare and was sealed in the Soul Dew over a century before the events of Pokémon Heroes, ends up freed due to the actions of Ash and the villains.
Films — Animated
In Disney's Aladdin, the Genie is a kind and good spirit who wants to help his masters. In Disney's version of the story, genies -- good and bad -- are naturally sealed. In the original Arabic folklore, sealed genies are, according to one of the stories in the Arabian Nights, the criminals of genie society. The lamps they are often found in are their prisons, and genies choose to grant wishes to show their gratitude for being released.
Genie: It's all part and parcel of the whole genie gig: PHENOMENAL COSMIC POWERS,ittybitty living space.
In Barbie & The Diamond Castle, Melody accidentally traps herself in a mirror while fleeing from the Big Bad's (literal) dragon, and keeps herself hidden inside, effectively becoming sealed good in a mirror. Until she's coaxed out by the singing of the main characters, of course.
Mulan: According to his backstory, Mushu the dragon was actually turned into an incense burner inside the Fa family altar as punishment by the Fa family ancestors for failing to do his job as a guardian the last time he was called. When Mulan decides to run off disguised as a male soldier, the Fa family ancestors send him to…awaken another guardian to help her. He fails and accidentally destroys the statue, and has to go himself. Fortunately, he's far from incompetent this time.
Films — Live-Action
The title character of the Austin Powers series was cryogenically preserved and revived in response to similar efforts by his evil counterpart, Dr. Evil.
In Dogma, keeping God on life support in the real world so She could not return to heaven and blink things back to normal could be seen as Sealed Good in a Can, in this case a more direct borrowing of Sealed Evil in a Can by the dark side.
In The Gamers: Dorkness Rising the... adventurers... players... whatever you may call them are officially on a mission to regain a cursed artifact for the High Priest of the local goddess of Lawful Good, Therin. Said High Priest is shown to have a powerful artifact of Lawful Good, which is later to be revealed the prison of Therin. The party destroys the prison, freeing the goddess and are rewarded by her afterward.
In The Garbage Pail Kids Movie, the titular Kids are trapped inside an outer space garbage can that lands on earth, and are discovered by an antiques store owner. He does his best to keep them in the can, but they always manage to find a way out. Much like the Animaniacs example below, the Kids aren't necessarily good, but they aren't evil either. A more apt definition would probably be Sealed Jerkass in a Can.
Sentinel Prime in Transformers: Dark of the Moon. He's been rusting away in the Ark since he crashed on the moon in The Sixties. It later turns out that he was actually a Sealed Evil in a Can, as he defected to the Decepticons before leaving Cybertron. After revealing this to his former comrades, he joins Megatron with a plan to enslave all humanity as a workforce to rebuild Cybertron.
Vangerdahast's subplot in the Forgotten Realms novel Elminster's Daughter involves him attempting to seal dragons in a can to protect Cormyr. (The country's previous Sealed Good was unsealed, then destroyed, in a prior war.) The subplot ends with Vangerdahast shapeshiftinghimself into a dragon, then sealing himself and a volunteer song dragon in the can.
In Guy Gavriel Kay's trilogy, The Fionavar Tapestry, King Arthur and Lancelot are both examples. King Arthur is awoken by one of the protagonists to fight the big bad. Arthur finds Lancelot under a mountain and wakes him. Guinevere is already present, Sealed in a Person-Shaped Can. Arthur is doomed to fight evil when called upon to do so, and the others are doomed with him to relive their own tragedy whenever he does so. Until the end of the trilogy, when they are freed as a result of a heroic sacrifice allowing Arthur to live to see the end of the battle for the first time averting part of the "doom."
Percy was kept asleep by Juno for several months until the time was right for him to go to Camp Jupiter.
Hazel's time in the Underworld also qualifies.
In Alan Dean Foster's Humanx Commonwealth novel Bloodhype, the Tar-Aiym Guardian, Peot, was charged with containing and finding a way to destroy the Vom, a planet-scouring Eldritch Abomination. Half a million years later, Peot is dormant and must be awakened in order to counter the Vom's renewed threat. Flinx turns out to be the key to accomplishing this.
Also by Rick Riordan, in Literature/Kane Chronicles good goddess Bast was locked a long time ago and it's main character's father who releases her. A bit subverted, though - it overlaps with Sealed Evil in a Can, because something very bad was imprisoned along with Bast - and escaped at exactly same moment.
Jim Knee in Septimus Heap was sent to Septimus as this and eventually succeeds, despite several incidents and being rather reluctant.
In the Back Story to William Shakespeare's The Tempest, Prospero releases Ariel from the cloven pine where he had been imprisoned for twelve years by the evil witch Sycorax for refusing to do her bidding. Ariel is thus bound to serve Prospero for twelve years to repay his debt.
In Beast Child, second book of Voyages Of The Flying Dragon , Manu, the so-called Titan boy is innocent and good, having being put away to serve the god-like being which has been split into Lenis and Missy.
Robert Jordan's Wheel of Time series has the Horn of Valere, which can summon the greatest heroes of the setting's history to kick righteous amounts of ass. The subversion being that the heroes obey whomever blew the horn — good or evil — until he dies. Double subverted when we find out that this actually isn't true; the heroes would never fight for the Dark One or his minions. Also the heroes aren't exactly sealed: they regularly get reincarnated on Earth and only the ones not currently alive are summoned.
The Doctor becomes one at the end of "The Pandorica Opens". The legends surrounding the box make it sound like a Sealed Evil, but the whole myth is a trap set up by his enemies, who are all under the mistaken impression that he's the one behind the universe-ending threat of the season. He gets out of it pretty quickly, but by that point said threat has already come true.
Who would have expected the depths of the planet Za'ha'dum, home of the evil Shadows in Babylon 5, to contain Lorien, The First One, who saves Sheridan's life and goes on to help the good guys? Though it wasn't so much sealed as waiting for someone worthy to find it.
In I Dream of Jeannie, Jeannie was sealed in a bottle for 2,000 years by the Blue Djinn as punishment for refusing to marry him.
It's implied that this was the case for the original Kamen Rider Kuuga. More than that, it was hinted he did it to himself and ages when he was discovered it is implied he was STILL ALIVE during all the time he was sealed up before the Grongi escaped and may have murdered him as soon as the seal was broken.
The Zyurangers in Kyoryu Sentai Zyuranger were put in suspended animation rooms in an underground temple, to make sure they would still be alive and ready to fight Bandora if someone released her.
Kai in Lexx starts and ends many episodes frozen in a stasis chamber, showing up to save the other characters in the nick of time. You know, because he's dead.
Zordon in Power Rangers. Technically he was in a "time warp" and broadcasting his face into a tube, but they freed the man by making him actually trapped in the tube. To make matters worse, the poor guy was kidnapped as soon as he was "released", and when he was rescued, he promptly had to commit a Heroic Sacrifice to save the day. Shoulda stuck with the time warp.
Ninjor from season three played the Sealed Good In A Can twice, once when he first appeared and again when Lord Zedd and Rita captured him and the Falconzord and sealed them away. He's currently still in his initial can thanks to the timewarp inflicted on the Earth.
The Outer Limits episode 'Sarcophagus' had an archeological dig find an alien in a tomb. Upon awakening, the friendly being was quite happy to find that humanity had come a long way from the cavemen that had attacked him on sight, forcing him to seal himself up to recover from his injuries. When there is a cave-in, the alien allows the two who had befriended him to seal themselves up, keeping them alive until they are finally rescued.
In Stargate SG-1, the progenitor of the Tokra, Egeria, was almost literally sealed in a can (a symbiont containment vessel) by her Goa'uld enemies. Egeria fared less well than usual — the humans who eventually found her were unable to tell her from any other queen Goa'uld and basically tortured her to death. Uhh... "Sorry"?
Sophia de Borghesse from Sabrina Goes To Rome. Since she cannot be with her lover, she seals herself inside a locket.
Many, many variations of the King in the Mountain myth, including King Arthur, Frederick Barbarossa and Bran the Blessed. These heroes are almost never sealed by an evil power; in fact they are generally sealed to "preserve" them to fight some coming evil or hardship. The promise that they will returning "at the time of their country's greatest need" is a key element of the myth in many cases.
On a related note, Excalibur itself might be considered an example, as this powerful weapon for Good was kept hidden by the Lady of the Lake until the right wielder came along. Like many cases where this trope applies to objects, it was Sealed In A Can Again after Arthur was through with it.
Some versions of the myth of Pandora's Box state that after all the evils of the world had been released from the box, there was just one more thing that remained in the box: Hope.
In Journey to the West, Monkey was first birthed from a giant stone egg. After gaining power and immortal indestructibility, he caused such trouble in Heaven that the Buddha sealed him under a mountain. Just five hundred years later, he was freed by Kuan Yin (Avalokiteshvara, the boddhisatva of compassion turned Chinese Goddess) after he promised to reform and help the monk Tripitaka/Xaunzang retrieve the Diamond Sutra from far in the West. This legend has been adapted many times in many ways, including Milo Manara's darkThe Young Ape, the rather BishounenSaiyuki, and Stephen Chow's A Chinese Odyssey films.
In Hesiod's Theogony, the Cyclopes and Hundred-Handers who were locked in Tartarus by their father Ouranos and later (again) by their brother Cronus, are freed by their nephew Zeus and the other Oympians when the Titans make war on the Gods, and in turn they forge weapons — most importanly, Zeus' thunderbolts — and help in the Titanomachy, the War with the Titans.
In module Q1 Queen of the Demonweb Pits, one possible encounter in Lolth's Web is a chance to rescue a ki-rin (powerful Lawful Good unicorn-like creature) trapped in a transparent cube that keeps it in a state of suspended animation. If rescued, the ki-rin will offer its services to its rescuers.
Module I12 Egg of the Phoenix. The ki-rin Da-weng allowed himself to be changed to stone so that at a future time he could be returned to normal and fight against Evil. If released, he gives the party an amulet that will allow them to summon him to aid them.
Benekander, a benign Mystaran Immortal, was Sealed inside the Mirror Shield for millennia before being released in time for the Wrath of the Immortals boxed set.
Etienne d'Amberville, an extremely powerful wizard Immortal from the Castle Amber adventure, must be freed from his tomb to complete the scenario successfully.
One way to destroy the Eye of Arik in Palace of the Silver Princess is to release the benign white dragon Ariksbane from another dimension, so it can shatter the evil gem with its icy breath weapon.
The Dragonlance setting is made of this trope: the Disks of Mishakal, the brass dragon Blaize, the rest of the good dragons, plus of course the dragonlances themselves. Half the campaign is uncanning sealed goods.
In most games for Solar characters, the Jade Prison in Exalted. More generally it's mixed at best; the Solar Exalted don't really answer to any authority and may or may not be good.
Lord Ith was imprisoned by Mairsil the Pretender during the years of The Dark (between the Sylex Blast and the Ice Age).
Avacyn, archangel and guardian of the humans of Innistrad, was sealed within the Helvault alongside the demon Griselbrand, until Thalia of Thraben was manipulated into freeing them both by Liliana Vess.
Technically, he's on psychic-fueled life support in a coma. His death would mean his rebirth, but a lot of bad things would happen in the mean time. So he's Sealed Good In A Can, with the Can being as vital to humanity as the Good. What, you thought we were joking when we said that 40k is GRIMDARK?
To a lesser extent than the Emperor are the Space Marine Dreadnoughts, and Eldar Wraithlords. On the plus side, you're now a near-immortal warrior that can crush hordes of enemies that plagued entire squads of your fellows in the palm of your hand... often literally. The downside? You have to be nearly dead (or for the Eldar, FULLY dead,) be rescued by your compatriots, and have been such a glorious badass among badasses that they plug you into a huge, lumbering war-machine. You're also hooked in there forever, or at least until the machine breaks and you die, and you tend to spend years, decades or centuries in between humongous battles in total stasis, hence fitting into this trope in multiple literal ways.
The Great Spirit Mata Nui's soul was sealed inside the Mask of Life by Makuta and thrown out of the universe. Upon setting things straight, he sealed himself back in, so that civilization could grow in its own pace, without a God.
The Toa Mata were put in stasis 100 000 years ago, so that were Mata Nui ever to be struck down, they could be immediately launched in their pods to hurry to his aid. Due to a malfunction, however, their canisters remained floating in the Endless Ocean for a 1000 years, under which time their flesh decayed and their memories were wiped. Good thing they could heal. This backstory was, by the way, part of LEGO's marketing: giving the toy containers and the figure's assembly actual storyline importance.
Used in the SNES classic ActRaiser; at the beginning of the game the forces of evil control the world, and your character is the Sealed Good In A Can. The game was remarkably lacking in controversy, since said character is strongly implied to be the Judeo-Christian God, or at least the local equivalent.
A Mess O Trouble (an excellent Mac WorldBuilder shareware Adventure Game) has two godlike creatures trapped inside time dilation bubbles in some ruins. You know from local historians (and abominations lying around in the ruins) that their civilization was practically constructed by a good creature and then fooled into nearly destroying itself by a bad creature. One is a beautiful Energy Being, the other a dull-looking lizard man. Guess which is which?
In Arcanum, the supposed Big Bad, Arronax, has been trapped in the Void repenting his crime for thousands of years: once found, he joins the party to take on the real Big Bad.
In the second game of the original Bard's Tale series, the Zen Master Arkast qualifies. (He singlehandedly took on Lagoth Zanta and his mercenary army before you showed up, and only failed by lack of being an unkillable Destiny Knight.) You don't technically have to free him, but travel into his can to group with him (and would thus normally bring him out with you). The start of the relevant poem in the manual: "A tale once told of ages gone, which bards once sung in deep despair / of he who fought the evil one, and cast his fate within the Snare..."
Alucard from Castlevania seals himself away on multiple occasions, seeing his powers as evil. He isn't intentionally a Sealed Badass in a Can, but when Dracula rises and the Belmonts are unable to act, he awakens anyway and goes out to deal with Dracula. After Julius Belmont's victory, he appears to be permanently unsealed.
JC Denton in Deus Ex: Invisible War. He merged with an ultra-powerful AI at the end of the first game, but the result was unstable. Before he could turn the world into a utopia, he had to go into cryogenic storage and wait for upgrades to be developed. Furthermore, his brother Paul was the test subject on some of these upgrades, which proved to be unsuccessful, meaning he also had to be put into cryogenic storage. The player can wake them both over the course of the game.
Golem named Shale from Dragon Age: Origins The Stone Prisoner DLC. Like other golems, she was a dwarven woman whose soul was transferred into the golem body to guard against the darkspawn threat, but was forced to spend hundreds of years dormant (but still awake and sentient in total darkness) until the Warden finds her control rod and re-activates her.
In Dragonfable, at the end of Chapter 2, the Hero of Lore is imprisoned in a block of ice by Jaania. The Hero finally breaks out many years later after a Time Skip, only to discover that the world has become very hostile towards magic and Jaania has become the new Big Bad.
The hero Melvin in Dragon Quest VII put himself to sleep so he would be alive to fight should the demon lord rise again.
In Duel Savior Destiny for a twist in the last route it turns out Aether Relics are previous Messiahs who have vowed to stop God from destroying the universe again.
In Fallout 3, James, the Lone Wanderer's father is a variation of this. After the death of his wife in childbirth, he abandoned his work on Project Purity for nineteen years to raise his child in the safety of Vault 101, making him a Big Good who chose to seal himself in a Can. The game kicks off when he decides to escape the Vault with the intention of restarting the Project, inadvertently forcing his child to follow him out into the Wasteland after him.
He actually does it again a little further in the game, a little more literally, when he manages to accidentally get himself stuck in the Vault 112 simulation Tranquility Lane.
Bahamut and Leviathan in Final Fantasy V were sealed along with the twelve legendary weapons and the ultimate magic spells after a battle against an evil wizard.
In Fire Emblem: Path of Radiance and Radiant Dawn, the goddess Yune is sealed in a medallion, locked away by her twin sister/other half Ashera, who found her chaotic whims too dangerous. While neither is technically good or evil, Yune is the goddess of chaos and Ashera represents order, and this, along with the fact that anyone (save for Mist, her mother, and members of the heron clan) who touches the medallion goes berserk, has given Yune somewhat of a bad reputation (as a "Dark God"). After her long sleep, Yune is warm and friendly to the humans, since she was always with them when in the medallion. Meanwhile, Ashera has become bitter after 780 years on the top of a inaccessible tower, and is portrayed closer to the Sealed Evil in a Can Yune was accused to be (particularly after passing judgment on all people when she realised they had been warring for all this time, where Yune decides to take the few remaining and defeat Ashera).
The events of the game Graffiti Kingdom are set in motion after the Prince Pixel releases both the good Pastel and the Devil from a wall mural when he decides to play around with the Graffiti Wand he finds lying adjacent to the mural chamber hidden in the castle.
It can also be said that Master Chief is sealed good in a can at the beginning of Halo: Combat Evolved.
The Forerunner, Didact, is sealed in the titular Cryptum for one thousand years as a meditative exile after his political defeat by the Builders. He is released early in the book.
Eventually subverted, however, as he ends up getting sealed into another Cryptum by the Librarian after going mad and converting a number of humans into Promethean Knights with which to combat the Flood.
The finale of Half-Life seals Gordon Freeman in a can, to be reheated and served in the sequel.
And at the end of Half-Life 2, he is resealed until Episode 1. Then things get weird, and either an Episode 3 or a third game has yet to come along and explain it all.
In the NES game The Krion Conquest, a good witch is released from a magic staff to fight off an Alien Invasion. Why she was sealed in it in the first place is unknown.
During the ending of The Legend of Spyro: The Eternal Night, Spyro, Cynder, and Sparx get trapped in the Well of Souls, resulting in Spyro using his Dragon Time powers to seal them in a crystal to save themselves. In the sequel, Dawn of the Dragon, taking place three years later, a group of Malefor's minions come and chisel them out, for a sacrifice days before Malefor's plan would have ultimately succeeded without their interference anyway.
In Mass Effect, it's mentioned that an eccentric Volus billionaire is spending his fortune excavating a planet of ruins for "lost beings of light" who are intended to fight "machine devils from beyond the stars". Unfortunately for the people of the galaxy, this apparently ended up being a Red Herring.
In the first game, it's revealed that many Protheans attempted to put themselves into stasis to survive, intending to awaken and rebuild the Empire once the Reapers had departed once and for all. Unfortunately for the people of Ilos, the Reaper's extermination took centuries to complete, the VI "Vigil" was forced to sacrifice non-essential personnel to maintain the others, to the point where only a dozen remained out of the hundreds put into stasis.
Javik in Mass Effect 3 was another such Prothean put into stasis on Eden Prime, with the VI "Victory" sacrificing the other survivors to maintain his pod. It got even worse as the damage caused by the Collectors meant that the revival procedure could only be activated manually, causing him to wait over 50,000 years before Shepard awoke him. By then, the latest Reaper invasion was already well underway.
Liara mentions in the third game having refined the Protheans' plan of using their Beacons as a warning, seeding many worlds with time capsules containing an archive with all galactic information, knowledge of the Reapers and plans for the Crucible weapon, in case the worse should happen and they fail to stop the Reapers. In the Refusal Ending, it's revealed that this did indeed work and allow the next Cycle to defeat the Reapers.
It's implied that the Protheans may have been responsible for sealing the Charon Relay in ice to intentionally keep Humanity undiscovered and isolated from the rest of the galaxy, possibly to prevent the Reapers discovering them if they had not advanced to the space-age by the next extermination Cycle. Or maybe just another ace in the hole if their plans with the Asari fell through.
The Biometal (or "Live Metal") from the Mega Man ZX series are the sealed memories of many past characters. Namely, Model X is obviously X, Model Z is Zero, And Models H, L, F, and P are the Guardians From Mega Man Zero.
Before that are X and Zero themselves, found in such a state at the beginning of their respective series.
In Puzzle Quest: Challenge of the Warlords, the player character and his/her allies must help the minotaurs revive their god, Lord Sartek, so that he can defeat the evil Lord Bane.
In Quest for Glory IV, you finally learn the fate of the legendary mage and Friend to All Living Things, Erana. She attempted to seal a Cosmic Horror that was invading the land, but only partially succeeded, and got sealed with it as well rather than miss her chance to do so. She's since been tormented by it for all that time, until the very end of the game.
In the early Sonic the Hedgehog games, Dr. Robotnik's plans usually involved sealing innocent creatures into his robots as power sources. Recently, he seems to have found another source of energy for them (Chaos Drives?). Why he didn't just use batteries in the first place is anyone's guess.
He might indeed use batteries, and the Small Furry Animals merely serve as the "intelligence" part of the robot. In other media, however, Robotnik relied upon the roboticization process. This other media includes Creator/Bioware's Sonic Chronicles: Dark Brotherhood.
First major straight example in the series is Tikal in Sonic Adventure. Sealed up right alongside Chaos, she gets released at the same time as god of destruction, and spends the rest of the game playing Exposition Fairy in the form of a glowing ball, and occasionally causing visions of Chaos's origin and nature. At the end she helps Chaos Ascend to a Higher Plane of Existence. Somehow.
Sonic Unleashed has this as well in the form of Chip, aka Light Gaia, who voluntarily sealed himself within the planet to bind his counterpart, Dark Gaia, and both were released incomplete when Eggman blew the planet open ahead of schedule — one's an amnesiac Exposition Fairy and the other a physically-scattered Cosmic Horror.
In Sonic and the Secret Rings the good genie, Shahra, is sealed inside a ring found by Sonic at the beginning of the game. Another cosmic being in the game, the evil Erazor Djinn, becomes Sealed Evil in a Can at the end of the game.
In Star Control 2: Ur-Quan Masters, races defeated by Ur-Quan Kzer-Za have choice between enrollment as battle thralls or imprisonment on their own homeworld under an impenetrable slave shield. One of the latter must be fetched out of can by the player in order to win.
Touhou has Byakuren, who was sealed away after trying to establish equality between youkai and humans. Bizarrely enough, you fight her as the final boss, after unsealing her, on purpose. Of course, given how the heroines usually behave, that probably isn't too surprising.
The druids in Warcraft III, whom the player must wake up during the Night Elf campaign. Some of whom are really, really cranky.
The Klaxxi are best described as Lawful EvilDefectors from Decadence who are opposing the abandonment of Social Darwinist values and the timing of the Mantid swarm-invasion, not that it is actually happening. Interestingly, they claim to be loyal servants of the Old Gods yet fight against the Sha, who come from the local Old God influence.
Serana from The Elder Scrolls V: Skyrim add-on Dawnguard is an ancient Friendly Neighborhood Vampire who rebelled against her vampire father, Lord Hakon, centuries ago and was sealed away with an Elder Scroll by her mother in order to protect them both from him. Although she's not particularly "good" (admitting freely that for her, the perks of being vampire royalty outweigh any moral compunctions), she seeks to thwart her father's omnicidal plans after being released from her imprisonment and becomes a loyal friend to the Dragonborn.
Abraham, the wizard who created the dewitchery diamond in El Goonish Shive. Sure, he almost kills Ellen because she was created by the diamond, but it's pretty obvious that she was the first non-evil thing created by it.
He also revises his statue's inscription to say I rise to atone for my sins after he realizes both good and evil creatures can be created by the diamond. This is a step above "I rise to reap what I have sown" which suggested destroying everything the diamond created.
Winnie from Free Spirit fears getting trapped in a mirror. A witch like her can not escape one by herself, and if no one lets her out before it breaks, she will die.
Sluggy Freelance: When the demons first conquered the world that became the Dimension of Pain, they sealed away all that world's goodness in a Zip-Lock bag and stored it in the Demon King's refrigerator.
Torg: I heard the story before, but I assumed it was metaphor.
In Beast Wars, stasis pods were the writer's means of introducing new characters. Whenever they needed a new character the character would usually come from a stasis pod, a sort of cocoon that provides life support for a spark and basic body for a transformer until they can scan an alt mode and become a fully conscious character. All the stasis pods in the show were Maximal by default, but were occasionally altered to give birth to Predacons. So in almost all cases stasis pods were essentially Sealed Good in a Can until they were altered, with one exception (Rampage).
In the prequel of Code Lyoko, Jeremie turned back on an abandoned Supercomputer inside which resides what he thinks at first is a benevolent A.I., Aelita. He will spend the next season trying to materialize her in the real world. This comes of course with its counterpart Sealed Evil in a Can.
In Futurama, it's revealed that Human Popsicle Fry was deliberately frozen by Nibbler, a member of the Precursors because he's The Chosen One, the only being capable of defeating the Brain-Spawn and preventing them from destroying the universe.
A Story Arc in Galaxy Rangers was about Tarkon's benevolent Master Computer that had been "sleeping" since an ancient war. The Heart of Tarkon controlled sophisticated defense systems for the planet and had to be "awakened" to repel a Crown invasion.
In one episode of Justice League, Despero is leeching off a Sealed Good's energy gradually to fuel his powers. When it's completely freed, he's toast.
Mummies Alive! had a royal prince and his four guards. When all five are slaughtered by the minions of the Evil Chancellor, the four guards are mummified and enchanted so that when the prince is reborn, they may awake to protect them. This is particularly important since the Sealed Evil in a Can has already been released. Further more they need to return to their sarcophagus's to recharge their powers.
The Autobots in the original Transformers cartoon, who were all sealed away inside a volcano with the Decepticons after both factions crashed into it in the distant past, making them all unconscious. It wasn't until the volcano's eruption that both were set free.
This more or less seems to be Metroplex's role in various recent continuities. He is often hidden and in stasis until unwittingly awakened by the Autobots.