Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Metal Gear Solid
Those who entered the game with little idea that there was a bad scenario, when you fail to restrain yourself from the torture, you realize you just killed Meryl. I played the rest of the game in a depression that I just killed Snake's love interest. Perhaps the most immersive moment in any game I played.
To make things worse, try playing the game and attempting to resist the torture, but having to surrender because you haven't saved for half of the game, and death there brings instant game over.
It gets sadder. You know how Campbell tells Meryl for most of the game that she's his niece? If you get the bad ending, he actually reveals that she's his daughter.
There have been many sad moments in video games before and after. And sometimes there have been vilains that got a bit of sympathy. But how often do you stay with an enemy you just shot, as she bleeds to death in the snow, in a dark and cold winter night. That day, Snake was the only one who was not crying, and only because he had no tears left. But we all knew that he also did inside.
The full line perfectly sums up Otacon's character at that point. Having just witnessed someone he loved die in front of him, by the hand of a man he's growing to respect and look up to, all he wants to know is how it came to that.
Otacon: What was she fighting for? (Snake rises to his feet) What are you fighting for? (Snake starts walking away from Sniper Wolf's body) What am I fighting for!? Snake: (turns to face Otacon) If we make it through this, I'll tell you!
The final scene of Metal Gear Solid when Snake tells Naomi that her brother told her to move on and doesn't tell her that Frank killed her parents.
The bad ending has Snake, in sheer badassery and manliness breaking down in tears and punching the floor over the fact that he can't protect anyone, and wherever he goes, people around him die.
And Otacon consoles him by saying that he and Sniper Wolf will meet up again in Heaven, so Dave and Meryl will, too. Such simple faith, after all the crap that Hal's been through. Such simple faith that people do go on to a better place, and that Snake is good enough to have a happily ever after.