Scariest movie for me was "The Omen", I saw that when I was 5. I also saw movies like "A nightmare on Elm Street", "Alien", "Jaws" and "Piranha" when I was that age, thanks to my older cousins next door... Many sleepless nights, although I ultimately became a fan of 80's horror flicks. Needless to say, I haven't been frightened from movies for a long time, I mostly just laugh whilst appreciating the way the directors create suspense and atmosphere
I agree Event Horizon was a nice surprise, I too was thinking it was going to be a Sci-fi flick. The opening scene of Nightmare II also has a special place in my mind.
Still nothing had an impact on me like the Omen, and to this day I still think it does a good job in creating a very evil atmosphere
My wife asked me why I carry a gun?, I said "Decepticons"... She laughed, I laughed, the toaster laughed, I shot the toaster. It was a good day.