The Ring, its one of my favorite movies of any genre.
I haven't seen the Other, but I read the book. I think I'll put it on Netflix. I've never thought of Sixth Sense as a scary movie, but it was really really good. M Night Shyamalan is one of my favorite movie makers.
Rob Zombie did a couple movies, one was called House of A Thousand Corpses, and it was exactly what a scary movie should be. The sequel was just plain stupid tho.
Blair Witch Project was one of the few movies that actually creeped me out.
Jaws scared the living daylights out of me when I was a kid.
The Exorcist, The Omen, and Rosemary's Baby are some of my favorites too. Also Evil Dead (the second Evil Dead was funny, intentionally even) and Night of the Living Dead.
Lost Highway is not your typical scary movie, I don't even know if it would be called such, but its seriously creepy.
Pumpkinhead is good, so is the original Wicker Man. And Hellraiser - Pinhead was cool!