I rated myself a nine, but the thing is...I don't get afraid of horror games while I'm actually playing them. The problem is I get really...really paranoid afterwards, when I'm trying to go to sleep or something like that.
I have a hyper-active imagination, and trust me...every little sound is something sneaking up to eat my head or something. Even if I can logically disprove it as nothing more than my fan blowing on a piece of paper, it still scares the hell out of me.
Only one time have I actually been frightened (scared, not startled) by a game. That would be in F.E.A.R. 2, when you're going through the school's bottom floor. Suddenly, the lights go out, and everything is evil-mode. Blood spattering the walls, ghosts flying out of the walls at you, lights flickering on and off, and this horrible, batshit crazy music screeching in your ears. Only way out is through a door slamming and opening again and again, with the only source of stable light on the other side. It's a mad, pants-wetting dash to the end, and it scared me shitless. Thankfully, I didn't actually wet my pants, just left me trembling and breathless for a few seconds. Then, when you're in a calm, clean, normal hallway...the screen goes red, and Alma appears out of nowhere and slams you against a wall. Fun stuff.