Dungeon Keeper, for obvious reasons.
Jizzraq
Diablo, how I dublicate items by accident by picking them up from behind the town portal.
SEGA Genesis is out of option? sigh
GTA 3 made me stop killing the cops in GTA 3 and later installments. In GTA and GTA 2 they were plain stick figures from above who tried to deter me from accomplishing my goals and my missions. I blasted them, set them on fire, whatever.
GTA 3 has changed. Giving them faces changed for me. What really did the click on me that I was driving on the park early in the game. Right above a hill I have spotted an older cop really late. He was old with gray hair, could've been 3 days before his retirement. I hit the brakes as hard as I could, didn't want to get a Wanted level. I eventually hit him with the car anyways, it knocked Mr. Officer off his feet. He got up, and he chose peace. He somehow chose to ignore this blatant offense and walked his way. He chose peace, to "live and let live".
In other games, well yeah, there is hardly a stopping for me. Counterstrike, Postal^2, Duke Nukem 3D, you name it. Even in old GTA games, old habits die hard. But GTA 3 or San Andreas? I am trying to get them not involved as much as possible. I still cannot forget the one officer, who has chosen peace.
Killing Narfi in Skyrim. Somebody performed a Dark Ritual to get a beggar killed? A mentally sick man living in the burned ruins of his childhood home? This bothered me.
When you threw rocks at a rabbit, hit one, and pick one up. How dare you?
I dared. I needed some warm quality mittens.
Noah's Ark on the NES by Konami. I don't know how common it is, but I think it is not.
Stalker Call of Pripyat after the main quest.