@The_Icon said:

" It has to be the Regenrator, when being trapped in the same room as it early on. And later when u had to flee and move the shevles to block him. Heart pounding moment in game!"

• Regenerator. When you face him again in the shelf room and you're trapped.....damn, I was freaking out since I was so low on ammo.
• Dividers. The first time you encounter one right after it kills somebody.....sweet Mother Mary. I had little to no ammo left and I spent it on his face pretty much, not knowing his legs were the weak spot. I had to throw suitcases at him to give me enough time to get out of the room. Then when I finally did all I hear is creepy whale sounds.
• Tentacles that come out of the walls. First time one grabbed me I didn't know you were supposed to shoot it. I was trying to break free and I was completely helpless.
• Not so much scary or even jump-scary, but the screaming guys on the walls are mildly disturbing and his instant kill move made me go "what the fuck?".

For me it's those really fast guys near the end of the game that just stand there twitching and then rush you at 10,000mph.

the one with too much free time 

" Possibly, if not definitely used to be a child. No grown person could have little hands and feet like that. "

Does the Leviathan count?
Cause that sucker made be crap my pants.
 
More than once.
 
I bought a new couch.

yea i'd say the twitchy fuckers made me double take on a number of occasions, but the necro that can re-grow limbs wins for best panic moment

" They were children, it's even stated in one of the logs. They experimented on babies with the necrovirus, and those were the results. "

The enemy that's stuck on the wall and basically amounts to a human with its stomach torn open and enemies pouring out of it. It reminds me of that one scene in The Mist where they find a man tied to a wall with a web who falls over and splits open to release a swarm of spiders. I'm not one to throw up during disgusting scenes but I came pretty damn close during that one and the first time I realized what those enemies on the walls were in Dead Space, I felt the same.

The super fast marine enemies, but any monster that would suddenly make me jump from chair is quite scary, haha.

geez, all these new users bumping old threads :\ 

ok honestly, Dead Space is not scary in the slightest, go play Condemned or Fatal Frame 2 if you want to be scared from a game.

" ok honestly, Dead Space is not scary in the slightest, go play Condemned or Fatal Frame 2 if you want to be scared from a game. "

" ok honestly, Dead Space is not scary in the slightest, go play Condemned or Fatal Frame 2 if you want to be scared from a game. "

Those ones which take your head off and supplement their own...    

The scariest part of this game is when I went to the store to buy it. this game sucked

" The scariest part of this game is when I went to the store to buy it. this game sucked "

Scary factor: the black guys that took way too much abuse before they went down. Scariest parts of survival horror games for me are when you just CAN'T kill the enemies. 
 
In terms of annoying/frustrating factor, it goes to the exploding hand monsters. Can't tell you the number of times one just walked up behind me and killed me in a single hit.

probably already mentioned but EASILY the guy that would keep regenerating.  The first time you run into him and have to run away through that area where you are having to move the walls out of the way = one of the most intense gaming moments I've had in awhile.  Heart was beating out of my chest.

i have a top 5
 
1.the regenerator  
note: who can forget when they first killed this basterd and he regenerated yep it was priceless.

2. the divider  
note: those things that look like they are made of tree branches or so.
 
3.the stasis slasher  
note: they are creepy when you first see one and they are ten times more scary then the necromorph when they sneak up on you.

4. necromorph note: these things scare the hell out of me when they sneak up on me. 
 
5. infector 
 note: these things dint scare me it was what they could do and the sounds of them doing it that scared me

" I was trying to find a picture but I couldn't. I think they begin appearing on chapter 9, but those tall lumbering guys that always seem to have a piece of ripped shirt on their shoulders. Then you shoot them and they break apart into small creatures similar to, what I perceive, as the flood from Halo. I don't know but they always appeared at the worst times and were quite creepy. Anyone find the other enemies scarier?P.S. If you can find a picture of what I'm talking about, go ahead and post it. "

I'm only on chapter 5 or so ...
but the ones that regenerate make me shit bricks and they piss me off no end!
But the little kiddie creatures? They're so cute yet oh so very WRONG at the very same time! 
But the bat things are just ARGH 
Whores....

" Yea Kendra said the super fast ones were fast because they fused with the built-in stasis that the soldiers had. Stasis slows things down, so why did it make them fast? "

" @Vinchenzo said:

" Yea Kendra said the super fast ones were fast because they fused with the built-in stasis that the soldiers had. Stasis slows things down, so why did it make them fast? "

Well, Isaac may be moving slowly compared to them.  The standard necromorphs that get put into stasis probably perceive Isaac as moving very quickly.   "

The fat ones with the nibblers inside it. I'm usually fighting other necromorphs while these ones are coming at me, and I'm always tense so I accidentally shot their stomach.

The ones stuck on the wall that lash out at you randomly. Or the weird "gloopy" ones that flip around on the ground. 

Regenerator... I just wanted to sever his legs and stasis him to hell in order to escape!