There are also some older classical works you might try, such as Modest Mussorgsky's Night on Bald Mountain.
Actually, Mussorgsky's Pictures at an Exhibition is an excellent composition, with some great atmospheric pieces, including The Baba Yaga and the heroic march The Great Gate of Kiev.
There are some good moody moments in the soundtrack to Brotherhood of the Wolf, and, of course, I've forgotten the composer, with apologies.
I don't recall if the soundtrack to the 1977 remake of Nosferatu, starring Klaus Kinski (been a while since I've seen the film), was particularly creepy, but it might be worth a look.
Soundtrack to Francis Coppola's Bram Stoker's Dracula, maybe? Seemed appropriately atmospheric at the time, as long as they didn't incorporate any dialogue tracks.
If I think of any more, I'll add them.
Warrior Poet