Amnesia, I gotta agree with. I'm not too far with it, but what I have played has been solid BPM increasing gold.
FEAR Files had its moments, but the original FEAR takes the cake both because of the game itself, but also because I'm playing it in a crowded dorm room with friends. It ran something like this:
I'm in a warehouse near the end of the game. I know there are ninjas nearby; I've beaten the game before and remember those invisible little bastards show up here. It's nearing midnight, the lights are out, the volume is cranked, and I'm high as a kite on a caffeine binge that has me strung tight. My roommate next to me knows what's about to happen as I'm looking about, and comments "Hey man, I'll call anything if I see it, alright?"
I turn and start telling him not to, that it's okay, when he suddenly bulges his eyes, points to the screen, and starts yelling "OH GOD THERE IT IS!"
Responding on a hair trigger, I wheel about and do the first thing that I always do when startled in an FPS: I clamp my finger on the trigger and keep it there. Three to five shotgun shells later I realize there's nothing there...hitting the reload button, I turn to my roommate and start yelling at him "GODDAMMIT Ian! Don't DO that!"
Right when I hit the word 'do' the windows explode, ninjas pour into the room, and my attention was not focused. Sudden loud noises and bad mans scared the hell outta me in a way I've never actually managed since in a video game.
So yeah. FEAR wins in my book, though Condemned and definitely Amnesia hold places of honor.