I lol'd.

Anyway, yeah, you don't need Crysis to play Warhead.

I'm unsure what the recommdned specs are, so think the Crysis recommended specs, only slightly lower.

I can think of 3 really annoyingly bad games. I'm undecided which is the absolute worst (probably Big Rigs)

1. Big Rigs (Fail incarnate)
2. Superman 64 (rings? seriously?)
3. H.E.D.Z. (was fun for all of 1 minute)

penumbra overture and black plague - Love these games.

fear

call of cthulhu

condemned

clive barker's undying

raunaq_morarka

This.

Adding to that:

The Silent Hill series
Fatal frame series (not played them, but apparently quite good)
SS2
Indigo Prophecy (or Fahrenheit)
S.T.A.L.K.E.R. has its moments.

I don't think things like Doom 3 are really that scary - something pops out at you to shock you, and then you kill it. Thats it.

Here's a brief summary of some of the Horror/Horror-esque games I know of:

The Penumbra's are good ones, you have a genuine fear of the enemies seeing you.
Doom 3 isn't so much scary; it rather just tries to shock you and make you jump.
Indigo Prophecy (Fahrenheit) has a few moments throughout
Vampire - The Masquerade: Bloodlines also has a few moments but not many unfortunately.
Silent Hill is a pretty good choice, although it hasn't aged all that well
Condemned - Scary at times, quite suspenseful.
Clive Barkers Undying & Jericho - Never played them myself, but apparently Undying is very good, Jericho - not as much.
S.T.A.L.K.E.R. - Very suspenseful and sometimes quite frightening.
F.E.A.R. (and expansions) seem to blend fast action with immersive horror quite well somehow. Give it a try.
Call of Cthulhu - Never played it but it looks good.
Sanitarium - Creepy. Very creepy.
The Thing - Haven't played this in aaages but I seem to remember it being very atmospheric.
System Shock 2 - Great game, and the scary elements play out well.

and one more not on PC:

Eternal Darkness (Gamecube) - Depending on how your 'sanity meter' is going, you see visions, hear odd sounds etc.
The game basically tries to **** with you, and it succeeds.

Meta Knight looks badass in a weird cutesy way

But Pyramid Head has to be up there somewhere -