I think some movies that had good twists were:
-saw
-fight club
-the sixth sense
-sweeney todd
-the usual suspects
-psycho
-memento
-the others

What about Identity? That was a sweeet ending!

oh memento, i forgot about that one! great ending

* Planet of the Apes (sorta a twist...both versions!)
* The Game
* The Crying Game (sorta)
* Existenz (if I remember correctly)
* Jacob's Ladder

Oh and two more:

* Sleepaway Camp (80s horror slasher)
* Seven

i like

1. secret window
2. saw 2
3. jagged edge
4. reeker
5. ghost


and i have gone brain dead i can't think of any more

My Favourite ending twists are

- Prestige
- The Village
- 12 Monkeys
- Saw
- Fight Club
- The Shawshank Redemption
- The Devil's Advocate
- Memento

haha Sleepaway Camp that movie was gold!

- Primal Fear
- Donnie Darko
- Solent Green

Identity (Definately)
The Game

I'll come back to add more as I think of them.

Secret Window...

the sixth sense, that is an unusual ending

Ok I think Enchanted had a great ending yet I knew that she was gonna end up with Dempsey's charther in the end so cheesy

Best twists in movies, that i can think of are:
Fight Club
Memento
The usual suspects
Chinatown
Primal Fear