Pyramid Head rapes things.

Pyramid Head wins.

I agree, from a gameplay standpoint I've never faced anything in a game that made me sweat in fear like those damn things do when you see them looking down at you or from around a corner to distract you while another one comes from behind to destroy you, absolutely terrifying.

And Pyramid Head while freaky as hell, gameplay wise isn't at all.  He's just big and stumbles around.  These things are scary as shit to play against, not just in cut scenes.

I'm not sure I remembered them in Dead Space and I've only just started playing DS2 so I can't really comment.

Anyway.

I also want to say Basilisks in the original Baldur's Gate. They were EVIL to fight if you didn't know how to prepare. Or actually any enemy past the 1nd floor in Durlag's Tower.

Try playing against the enemies in Amnesia: The Dark Decent. You rarely encounter it, but you're constantly on edge because you can't fight back and your only options are to run or hide. Trying to fight means death.

On higher dificulties even if your back is against a wall they will climb over any metal shelves or obstacles next to you while another strait charges you to distract.  Actually some pretty damn impressive AI. On the lower difficulties though this strategy definatley will work

Um not really, I've already beaten the game and every single time you encounter them your in an open labyrinth area for the direct reason of them NOT being able to do that.  Like I said it works VERY well on lower settings but on higher setting they don't single charge, multiple do at once.  Its litteraly impossibe to stop them both simultaniously so your best bet is to Stasis one then run from the other while taking shots at the one you've stasised. 

I haaate those things. The first time you face them, I died a few times until I just backed myself to the door (in the church) and used my line gun to kill them. Best weapon to use against them is either the line gun that is strong enough to kill them one shot or the detonator gun (forgot the name)....Still pretty annoying as they attack in packs.

This. The fact that you can possibly kill these stalkers makes them sound not-scary.

Not really, just different kinds of scary.  In Amnesia the enemies are terrifying cause they are basically impossible to defeat.  In Dead Space the Stalkers are terrifying because they are hard as hell and confusing to fight and your FORCED to.  You don't have a choice so its freaky cause you know, damn I have to somehow get myself out of this.

Both hella scary just in different ways.