Oldboy: this movie is MESSED up!

Well, my vacation time has allowed me to watch my first movie in my backed-up NetFlix queue, the Korean psychodrama, Oldboy.
It's a great thriller. It starts with an opening scene of the main character, Dae-Su, holding a man's tie as he precariously hangs over a side of a building. He's all standing still and dramatic and then he says something to the effect of, "Let me tell you my story". The movie is in Korean with English subtitles.
The story pretty much is about this guy, Dae-Su, who is suddenly locked up for some unknown reason and then, just as suddenly, is released 15 years later. The beginning part of the movie, you hear his inner dialog and what he's thinking as he tries to figure out the puzzle of who did this to him.
When he gets out, he's wearing a new suit, is given a wad-load of cash and meets some chic, Mi-Do in a sushi restaurant. The rest of the movie is basically how he figures out what happened to him and how he really wants to seek revenge on those who imprisoned him.
I can't give too much of the story away, but suffice to say that the ending is incredible, something that you weren't expecting.
It blew me away.
I give it 4 out of 5 stars.