Bubba Ho-Tep: The premise of Elvis and Black JFK vs. the Mummy may sound nutty but it's a pretty special little movie. It deals with the issues of aging and there's more there than meets the eye. It actually made my wife cry.
Shaun of the Dead: Really fun movie. I think its the best zombie movie since the original Dawn of the Dead.
High Tension: I figured out the twist long before I was supposed to but it was still really entertaining and original.
The Descent: What made it special for me was the original ending, which of course was changed and dumbed down for the U.S. release.
Them (aka Ils): A French horror film that IMO is the best of the home invasion genre. I really enjoyed this one.
Joshua: It's a slow-burner and probably wouldn't be to everyone's taste. For some reason I found the atmosphere reminiscent of Rosemary's Baby although the stories aren't at all similar.
The Mist: Frank Darabont is one of my favorite filmmakers and this movie was a real departure for him. The movie is fantastic and it has a very powerful ending. One of the few Stephen King projects where the movie surpasses the the book, or in this case, the novella.
American Psycho: I don't know if everyone considers this a horror film, but I do. A great story about the coldness of elitism.