Antichrist (2009) - One of the most disturbing films I have ever seen, and it's pretty difficult to scare me with a film since I've been studying them for years on end so I know they aren't real. X3 But gawd, this film is just bloody wrong in every single way possible. It has fantastic acting, though, but the story and the way the characters act within it are just wrong.
Possession (1981) - Please don't watch this film. It put me off spaghetti for a month.