6. Psycho
Sure, a lot of people have problems with the overly expository finale of Alfred Hitchcock's superb slasher flick Psycho - the explanation of every last detail to us by a psychiatrist feels a little on the nose - but the scintilating, disturbing final image is surely burned into the psyche of anyone who has watched the film. Norman Bates (Anthony Perkins), the man responsible for the Bates Motel murders, sits alone in his cell, covered by a blanket and listening to the voice of his dead mother inside his head. As she continues to discuss the situation with him, he looks down to a fly, and the image returns to Norman for the very last, lingering shot. Mrs. Bates says "She wouldn't even harm a fly", to which Norman grins manically into the camera, before the image of his face briefly morphs with that of his mother's skeletal corpse. His mother has completely taken hold of his personality, and there is nothing left. Granted, there is an additional image of Marion Crane's car being pulled from the swamp (with the words "The End" superimposed over it), but it's this glimpse of Norman that is the real dramatic crux for the film.