I'm going way back, almost 30 years.
Phantasmagoria 2: The Puzzle of Flesh
Assuming I remember correctly, some ways into the game, you, the player, realizes your character is the one who has been committing all the horrible, tortures and murders. I stopped playing at that point. I never play "evil". For instance, in FO4, I never took over the Commonwealth with the raiders, raiders are always cannon fodder.
So, it didn't really change my life, per se, but I have remembered it all these years, and still have no interest in finishing the game.