Hey guys, I want to write an article for a games website about some horror experiences in gaming and thought, why not ask GOG! What were your personally best parts of your favourite scary games, shocker moments, or even just all-round ambiance? Personally for me I'm a big Silent Hill fan, but modern horror is getting better with titles like Penumbra and Amnesia. I love shockers anyway and have been out of the loop for a while, tell us your creepy gaming moments!

Also a big fan of the Silent Hill series, but I remember been more scared with some moments in the Fatal Frame series than Silent Hill... (O_O)

that scene in silent hill 3 when heather talks on the phone with the strange guy wishing her a happy birthday, that creeped me out.

Zombies in Thief 1.

F'ck no!

Mmm~ System Shock 2 was really scary for me.
SHODAN always spooked me with it's radio chatter..

Towards the end of the first Marine level of AvP2, after a massive build-up of tension there is a bit in a dark corridor where the ceiling caves in just in front of you, and what appears to be an alien head swings down through the hole. Messed me up!

Slender Game! It fucked me up!

I might remember others later, but these are the first ones that came to mind:
Silent Hill 2 - The carnival guy speaking during the elevator ride
Silent Hill 3 - The haunted house attraction

My all-time favourite horror game is the first F.E.A.R. It has a really scary atmosphere and made me quite jumpy while playing it (much to the amusement of my wife). Especially Alma kept creeping me out. ... Unfortunately the later F.E.A.R. games couldn't keept up to the great first game.

The Penumbra-Series you mention was also quite scary. You could really feel the fear of the protagonist when he was hiding from the freaky monsters. I didn't play Amnesia yet, unfortunately, but you definitely should give Slender a try.

And then there are some games that are not scary as such, but still have a very nice horror atmosphere. Here I'm thinking especially of The 7-th guest and Sanitarium. (both available here on GoG)

I don't why everytime I see the giant worm from Alone in the Dark, it gives me the creeps.
Another possibility is the Ocean House Hotel from Vampire Bloodlines,

That level + closed headphones + a gorgeous female cat, biding her time = heart attack

Thief 3, right?

Drowned Nations in Planescape: Torment (faces in walls).
Certain mission briefings in Immortal Defense if you don't know what kind of game it is.
Eye of the Beholder 2, specifically the lower dungeons and the final level.

Heh, Ocean House, good times. I played that level with the camera zoomed out as far as possible and myself sitting as far from my laptop as I could. xD