AKA topic - "What movies are based on Twilight Zone episodes".

However I personally don't count Vanilla Sky, as I could get any random script and just add that ending and go AH HA!
Memento is an awesome movie, although for some stupid reason the track markers for just the first three scenes on the DVD(R4) are in the *middle* of the scenes rather than on the ends. So you can watch it "backwards" right up until you get near the "end".
New ones:
- The Village
- A Beautiful Mind
- Enigma
- Screamers
- Dark City
- Planet of the Apes (as with Star Wars, how could you *not* know)
- The Lord Of The Rings has two particular twists. Sharky's identity would have been the third had it not been cut.
Honourable mentions (small but cool twists):
- The Rocky Horror Picture Show
- The Princess Bride
- Ocean's 11
- Blade Runner
- the Angel episode where Conner is born.
- and of course, "To Serve Man"...