* The death of E-102 "Gamma" at the end of his story in ''Sonic Adventure.'' Gamma the bird is free, Gamma the robot however deactivated and exploded in a large fireball. Though what really makes it is [[http://www.youtube.com/watch?v=9-9FaXg5NOk the music]].
** In the actual game, one scene between Amy and Gamma becomes a tearjerker in retrospect. Amy expresses hope that she and Gamma will meet again, but that is the last time they ever see each other.
** The cutscene prior to the battle is particularly chilling, as Gamma assesses the remaining units he must destroy, he looks through flashback images in his memory banks, one of Beta being redesigned... and one of himself. As he looks at his hand and designates himself, we know Gamma's fate is sealed. The lack of background noise aside from a gentle sea wave greatly compliments the somber revelation:
-->'''Gamma:''' Units remaining...''*looks at hand*''...[[WhamLine Gamma]]...Beta."
** Gamma's theme itself becomes hard to listen to after you beat his story, especially that ending synth melody.
** The prison cutscene. The supposedly intimidating robot confronts Amy for the bird, after she refuses, and in desperation, actually begs him to let it go. Gamma starts feeling pain from his new-found empathy, going berserk before letting them out of their cell and ordering them to escape. He slumps over the door switch, dumbfounded and guilt-ridden at disobeying his master's orders, though Amy shows sympathy and offers him her friendship before leaving. Gamma's heartwrenching theme playing in the background helps none.
*** Amy, despite being locked away and under interrogation, can only feel pity for Gamma over his confusion over why she cares for Birdie so much:
-->'''Amy:''' ''*sadly*'' I feel sorry for you. Eggman failed to give you feelings.
** After his brethren fail to collect Froggy, Eggman angrily teleports them out of his sight to be made into something useful (which, as Gamma discovers through Beta, isn't a pleasant process at all). Before he vanishes in front of Gamma's eyes, a pained Delta turns to look at him. While no dialogue is said, most sources and media imply that Gamma felt guilty for dooming his brothers.
** Keep in mind, the E-100 units in Sonic Adventure were essentially ''siblings.'' Gamma was forced to kill the only people he ever cared for -- with the exception of Amy and his creator Eggman (who he probably saw has his ''father'') -- for the greater good of saving the birdies from a FateWorseThanDeath.
*** Actually, Gamma is only aware of the birdie inside of him and another of his siblings when he defeats E-102 Beta MkII and frees that birdie. On top of that, Gamma has seen with Beta that Robotnik wouldn't [[YouHaveOutlivedYourUsefulness give higher orders to the failures among his machines]]. Instead, Gamma faced his siblings (E-103 Delta, E-104 Epsilon, and E-105 Zeta) in order to [[DefeatMeansFriendship rescue them]] from their being little more than EliteMooks to Robotnik. Yet the mission is to "Destroy" the corresponding member of the E-series and the victory cutscenes shows their [[FamilyUnfriendlyDeath absolute death-by-explosion]]. This actually makes Gamma's play-through a larger tear-jerker because it depicts a childlike innocence concerning what death really is. And this innocence is only broken at the end when he is able to actually understand [[HeroicSacrifice the cost of doing the right thing]]. With bonus tear-jerker points if you [[AlternateCharacterInterpretation carry out the implication that his finally understanding what death is]] [[RedemptionEqualsDeath means that he has decided to join the rest of his family which he was responsible for killing]].
** The worst of it all is how there is no one to mourn Gamma. His cohorts are all dead by his hand, Eggman vanished from the storyline but wouldn't take kindly to hearing that his robot had gone rogue. Sonic, Tails, Knuckles and Big knew him as little more than a generic badnik of Eggman's, and Amy never gets to see him again like she wanted (par the ''Sonic X'' adaptation, though that is [[BreakTheCutie just as heartbreaking]]). The only solace is (if Gamma and the bird are separate entities) that the bird family might be thankful to him. If they're intelligent enough.
* Speaking of ''VideoGame/SonicAdventure'' music, ''[[http://www.youtube.com/watch?v=jPbtnGU30fE Sadness]]'' is truly ExactlyWhatItSaysOnTheTin.
* [[spoiler: Tikal's implied death.]]
* [[WoobieDestroyerOfWorlds Chaos.]] Once a peaceful soul who cared for Chao and befriended Tikal, Chaos eventually lost it after witnessing [[spoiler: Pachacamac invading and slaughtering the very creatures he tried to protect. Driven over the DespairEventHorizon, he sought vengeance on the very Echidnas that had caused the catastrophe.]] Then he's sealed inside the Master Emerald to prevent him from harming anybody else, which means he spends [[AndIMustScream 4000 years trapped in a cocoon of anguish and sorrow.]] Even Sonic sympathises with him.
-->'''Tikal:''' He must be sealed in the Master Emerald now.
-->'''Sonic:''' How can that help? It won't change how he feels inside will it? His heart will still remain in turmoil, and his anger just won't vanish! He'll just be trapped forever.
** To think that Sonic wants to help SAVE the God of Destruction is heart wrenching to think about. All throughout the game, he saw Chaos as this huge enemy, determined to stop him and Eggman from destroying the world. To go from that over the course of the game, to understanding Chaos and wanting to save him could definitely count as a tearjerker.
** To say nothing of poor Tikal [[spoiler: who sealed herself in the Master Emerald with him, just after her entire clan turned on her and the Chao and were destroyed by Chaos. The implication was that in her sorrow she intended to doom herself to that state again to save everyone, and while she given a more peaceful alternative, her original sacrifice still seemingly cost her mortal form.]]
* To a certain extent, Knuckles' predicament. He is forced to stay on Angel Island, guarding the Master Emerald. Bound by his duty to his species and to the gem itself, he is always tied to it, unable to stray too far. He will never be free like Sonic and Tails are.
* In one of Big's recaps, he wonders to himself if Froggy keeps running away because he doesn't like him anymore.