Promethius (2012) - I'm a total Alien fanboy (except for Resurrection) and I loved this
Ju-on: The Grudge (2002) - I'd seen the American version but this was the first time I'd seen the original. Very creepy.
Phone (2002) - South Korean horror movie. Great atmosphere, characters, everything.
Noroi: The Curse (2005) - more J-horror. Scariest movie I saw all year
The Mummy: Tomb of the Dragon Emperor (2008) - great addition to the franchise.
American Mary (2012) - stylish and original, and Katharine Isabelle does a great job in the title role.