Depends on just what you find disturbing? A couple of not that well known but great(imo) horrors are Deathwatch (set in a WWI bunker) and The Bunker (similar to Deathwatch). other good horrors are the ORIGINAL japanese version of The Ring and a good gory one is The Descent.
No idea what I will be doing on Halloween yet. I might dig out Project Zero 1 and 2 (if you havent played these and own a PS2 then these are sure to make you jump at least once while playing them, if they dont - check to make sure you have a pulse lol) or Silent Hill 2, 3 and 4.
BTW nice Donnie Darko sig Daz