Magic Magic
An odd one this - it has all the trappings of a horror movie, but charts the descent of a disturbed young woman into a breakdown with no supernatural or slasher elements at all. The protagonist is taken on holiday by her sister, who is mysteriously called away and left with the sister's group of friends, including the very unpleasant Brink (played by Michael Cera). Jetlagged, and on the outside of the group, she struggles to fit in, and descends into madness, with tragic consequences. It's a film that divides audiences, and I think most chatters would be on the side of those not liking it - I'm with Peter Bradshaw, whose description of it as "...a disquieting and unnervingly plausible depiction of mental breakdown. " is accurate.