Favorite Movie with Surprising Ending.

My favorite movie that had a surprising ending was The Stepfather. It is a about a man that would have different identities, marry into a family, and then kill them all. The current family he was with, the mother had a son that came back from military school, and he kinda knew that his stepfather was off. He ended up killing the neighbor and his new wife kids father because they found out who he really was. It was a very stormy night when the son and stepfather were fighting on top of house when they both fell. It was a surprising ending because when the son woke up from a coma, his mother told him that his “step father” was gone. They never knew where he went.