Arx Fatalis. Undead and spiders are pretty common in RPGs and usually only good for a yawn, but put them in a dark 3D environment with narrow tunnels and foggy catacombs and spice it with immensely immersive atmosphere, and it becomes a whole different matter. :D

How come no one has mentioned System shock 1 or 2? Both had me turning way too often thinking something was sneaking up on me. And plenty of times had the feeling of "I do not want to go through that door, something's going to get me"

And Doom 3? Is it paranoia when you KNOW there's going to be something behind you? You know it's out to get you. And the first thing to do when you hear a noise in Doom 3 is to turn around and take out the thing which spawned in behind you.

Or are we going with actual paranoia? You think something's out to get you, to creep up behind you. And it never is?

For me it's the Silent Hill games! Always give me the creeps. I remember playing at night and couldn't immediately go to sleep after that, so I relaxed a bit rewatching some TNG.

Thanks for the info, from now on I can say 'I played thief until I reached The Craddle and then I got mad and had to stop playing, twas a neat experience I daresay'.
Seriously, I don't regret not finishing the game at all.

The very first Resident Evil on Playstation.. At the time my schoolmate let me borrow the game but i did not have any memory card so yeah.. Paranoid with HUNTERS cutting off your heads clean, bloody screen YOU ARE DEAD.. Every corner, monster, or worse boss encounter was a flip, hell, no save!!

the first half of King's Quest 3 - mainly because when I first was going through that game I was always looking over my shoulder(so to speak) for that damn wizard never sure when he was going to return from his trips and catch me somewhere I was not supposed to be or with something that I'm not supposed to have. Still to this day even knowing his pattern and how long he stays gone I still get paranoid that I'm going to run out of time.

Silent Hill 2 -That game was just creepy as hell and unlike Resident evil I was honestly on the edge of my seat wondering what was out there due to the pacing and tension it built.

Penumbra 1 and 2

Amnesia

Project Firestart on the Commodore 64

I got that game at a thrift store last month i have yet to play it