Memento
This neo-noir thriller follows amnesiac Leonard (Guy Pearce) as he attempts to track down the man who killed his wife. Leonard cannot remember anything after his accident, and his memory resets every fifteen minutes. In the end, Leonard is devastated to learn that he is the man who murdered his wife.
The Others
Although the audience is led to believe that the house is haunted by some sort of vindictive ghost, the famous twist ending of The Others reveals that Grace and her children, along with their servants, are actually the ghosts. Grace murdered her children and committed suicide after learning of her husband's death in World War II.