8. Lost to the Curse - Dragon Age: Origins
The gritty storyline of Dragon Age: Origins has plenty of moments where the morals of the Grey Warden are tested, and they have to deal with some pretty heavy consequences for their actions. Well, except for one side mission, which will make you feel bad regardless of what you do.
Lost to the Curse is a quest in which the Grey Warden has to find the missing wife of a Dalish hunter named Danyla. Upon finding Danyla, it will turn out that the woman has been turned into a werewolf and doesn't want to come back in fear of hurting her husband.
Danyla will ask the Warden to kill her and lie to her husband about her fate. The player has the option to refuse and tell Danyla to come back, but this will only provoke her and cause her to attack the Warden, forcing them to kill her anyway.
Nothing you do can spare Danyla's life or soothe her husband's grief. But the worst part is, at the end of the Dalish storyline, you can actually cure all the werewolves, which means that Danyla might have come back to her husband anyway, if you just hadn't picked up the quest in the first place.