I'll copy and paste what I posted on Darth's thread.
Oldboy: 5/5
Just watched it this morning on Netflix, and wow, this movie was kick-ass. Awesome acting, great narrating voice, well-paced, fantastic characters, twists that just gets to you (you'll understand when you see it), etc. It's a revenge story, but it's an interesting one at that. Also, the fight scene was fucking awesome, and I'm amazed it was done in one continuous take.
Highly recommended. I put it up there with Memento, The Good, The Bad and The Ugly, and The Godfather. Brilliant movie.
It's a foreign film, but the one on Netflix was dubbed. So for those who dislike reading, you have nothing to worry about.