Here's the thing....
Jump scares are usually easy to prepare yourself for. Especially in a shooty game.
As much as Dead Space 1 was a GREAT game, and is actually worthy (IMO) of being called a survival horror game, I was only scared by it twice. The first time involved me keeping an eye on a corpse in the morgue that (Being the genry savvy gamer I am) I was sure was going to come to life...only to get sneak attacked from behind (after which I wasn't taken by surprise again because I would occasionally check behind me once in a while). And the second time was when the first "speed demon" thing came screaming around the corner incredibly fast, and I was like "HOLYSHITWHATISTHATHOWDOIKILLITDIEDIEDIE".
Now, I'm willing to give Dead Space a pass, because it at least TRIED to have good atmosphere, and although I switched to my "expect and counter all incoming ambushes" mindset almost immediately, it kept trying to unsettle me. It failed, but it made such a good effort that I give it a pass. It was a great game, and it at least kept me stressed, on my toes, and properly paranoid at all times.
Maybe it's my fault I wasn't scared at all because of the "hyper focused, paranoid, expect all ambushes and counter them" mindset I developed and immediately find myself slipping into whenever I play a horror game. Then again that's the only reason I can even PLAY horror games. I used to be a total wuss and would not be able to SLEEP after playing the RE1 remake for a half hour at a friend's place. Without that mindset...I wouldn't be able to play scary games AT ALL. The only thing that can crack it is to pull the silent hill style "make the player doubt everything" thing and REALLY build up the tension until I'm thinking "DAMMIT SOMETHING ANYTHING ATTACK ME I NEED TO RELEASE MY PENT UP REFLEXES" and then hit me.
Or, you make me ridiculously vulnerable.
I STILL am not able to play Amnesia or Slender.