Top 10 in reverse order:-
10) Bunker
9) Psycho
8) Hellraiser
7) Blair Witch Project
6) Return of the Living Dead (Comedy Horror)
5) Candyman
4) Event Horizon (SciFi Horror)
3) Alien (SciFi Horror)
2) Day of the Dead (anything else from the series, but this one in particular)
1) The Hole
Some have been mentioned, others woefully missing. Some are guilty pleasures, others just pure classic. Some are before my time, some I gave up regular film viewing before they came out.
Recently I've enjoyed Fear of the Dark, House of 1000 Corpses, Forget Me Not and Perehelion and while it's not a personal favourite, I'm surprised that Battleship Royale isn't on anyones' list. IMHO, Ringu is massively superior to the U.S. Ring.
Just a few thoughts. ^_^