Some good thiller/scary movies mentioned already that i like:
8mm
Alien
The Exorists
The Thing
The Hitcher- man, i forgot about that one
Prince of Darkness- good, creepy movie
Only two movies have given me nightmares after seeing them.
Jaws- i was about 10 yrs old
1984- i don't like rats!!!
I think i should watch Event Horizon again. I wasn't impressed the first time i watched it.