Japanese versions of Dark Water and The Ring, Thai version of The Eye... I don't know where you may find those, but it's possible to. Hmm... Silent Hill, it's not too scary, but grotesque and strange. If you like psychological thrillers / action / freaky things, Resident Evil movies aren't bad. Of course, the American versions of The Eye, Dark Water, and The Ring, they aren't quite as horrifying, but they aren't too bad. The Grudge, American or Japanese version... and last, but not least; Willy Wonka and the Chocolate Factory, SCARIEST movie in the world. D':
EDIT: Rosemary's Baby, Troll 2 is effed up, horrible acting, but it's amusing, The Shining, Cloverfield was a GREAT movie, Jacob's Ladder, Amityville Horror, Pan's Labyrinth, Videodrome (effed up movie), Pet Sematary, etc.