Best "never saw it coming" ending to a movie!

[GonzoStyle]

Remember watching a film and figuring great it's just gonna be the same 'hollywood' happy fuckin ending, where everyone is happy and the bad guy gets his in the end, bullshit. Then you get totally blown away by the ending of the film. Now it has to be the ending, a mindfuck twist that happens 45 minutes before the film ends doesn't count. Also it has to be something that you could not see coming. It can't be just a great finale to a film like scarface or the wild bunch.

Here's my top 5.

1. The Usual Suspects.
2. The Sixth Sense
3. Se7en
4. The Manchurian Candidate
5. Primal Fear

notable mentions:
Planet Of The Apes (1968), Memento, Arlington Road, Fight Club.