Tear Jerker / StarCraft II: Wings of Liberty

• Donny's breakdown. All the more compelling because up to that point Donny had been carrying water of Mengsk like it was going out of style, and even Kate, who would normally jump at any chance to get back at Donny for being a dickhead to her for the majority of the story, chooses not to rub this one in his face:
  "I had a brother on Tarsonis, I had a brother...."
• Though you may have had a pretty good idea that something like it would happen, you probably still felt bad when Raynor had to kill Tychus to defend deinfested Kerrigan. And to make the matter worse, this could all be Tychus consciously deciding that it's better to die by Raynor's hands than to give Mengsk that satisfaction. It becomes very obvious on a repeat playthrough that his expression when he asks Horner "You tellin' me they were shacked up?" isn't surprise, it's horror. Tychus realized right then this wasn't a matter of just convincing Raynor to get the artifacts and then doing his job at the end, and he spends the whole game trying to convince Jim that Kerrigan needs to die, so they won't cross each other at the end. To no avail.
• The entirety of In Utter Darkness, with the Terrans technically extinct and the Protoss holding out in their last base, thanks to all that hammy dialogue. The thought that you must technically lose (let the Zerg destroy your troops and base) once the Archive is sealed and the Zerg kill counter has reached 1500 to win didn't help either.
  • In particular, the Protoss being informed that, by killing Kerrigan, they doomed the universe.
  Artanis: Kerrigan... How could we have known...
  • And then, after Protoss are destroyed, Amon destroys Zerg. All three playable races are wiped now...
• The reason Infested Terrans have timed life. it's how long it takes them to work up enough Heroic Willpower to kill themselves.
• The flashback where we have to watch Mengsk's betrayal of Kerrigan from her perspective, literally the exact dialogue from the first game. Surrounded by zerg, her team all dead, running out of energy and ammo and backed into a corner as she slowly realizes that help isn't coming. We watch her break and she just stands there as the zerg finally catch up to her, resigned to her death.
• Jim Raynor's transformation from an idealistic Cowboy Cop to an embittered alcoholic.