I'm not gonna use spoiler tags since this game is so old no one will be able to play it anyway on today's hardware so...
Harvester:
In the end scene you kill the girl you like while she's begging you (in her underwear of course) to spare her life. You rip out her spinal column and then wake up to realize that the whole game was a simulation to train you to be a serial killer.
And that was to get the "good" ending.
Here's the video for it:
Yeah, nice and dated looking but the mind "f" was that I didn't expect to get the better ending from killing the girl instead of saving her.