Interesting plot.
Great acting.
Beautiful cinematography.
Miserable and depressing.
Awesome fight scene.
Superb music.

It was a really good film, although it lost me at a few points. The twist was excellent.

Much more thoughtful than a Hollywood movie would perform following that premise and more than just a "revenge film".

I was stunned into silence for ten minutes after the film ended. Honestly, one of the best I've ever seen. The plot had me guessing all the way through, and the twist was so brutal. Absolute genius cinema. I could praise Oldboy for days!