The Human Centipede: First Sequence (2009)

Neat idea and a great lesson on how effective the power of suggestion can be. Sure, it's got an evil German doctor, bimbo actresses who can't act, and plenty of gore. But what really makes this slightly better than your average horror film is the welcome addition of camp humor, a mainstay of 70s horror. That, and the thought of facial disfigurement, anal tearing, and shit eating.