Best twist endings in movies: "The Sixth Sense."

The best twist endings in movies? Those that enhance the film's previous two hours without rendering them moot.

From Alfred Hitchcock's "Psycho" in 1960 to modern classics like "Memento," "The Sixth Sense" and "The Usual Suspects," twist endings have shocked audiences for decades. Who can forget that he was dead the entire time? Or that she was dead the entire time? Or that he was the criminal mastermind? Or that they were all in his mind? Or that you blew it up?

Below, enjoy 15 of the greatest twist endings in movie history.