Don't read any reviews! (except this one)

"Identity" is the kind of movie you do NOT want to read about before you see it because spoilers are everywhere. That being said, I will tell you that the film is an extremely effective little psychological thriller that I really enjoyed because I figured it out - in 3 stages - from the clues given, and I got to have the supreme and intense pleasure of indeed seeing it play out the way I had deduced that it must. So for me, the ending was not a surprise (it was the only logical conclusion), but this didn't ruin the film for me or make it predictable in a bad way; in fact it actually enhanced the reward of the experience.

The movie doesn't have enough psychological nuance to make it a masterpiece (like, for example "The Sixth Sense") but I still got the chills at the end even though I had figured it out, and this speaks volumes about its effectiveness.