If you don't mind watch subtitled films, and have a fairly strong stomach, “Oldboy” is a Korean movie about Oh Dae-su, who's after revenge for being imprisoned in a room for fifteen years and being framed for the murder of his wife. After his release, his erstwhile kidnapper offers him a deal: if he can work out why he was imprisoned, the kidnapper will commit suicide; if he can't the kidnapper will kill Mido, the young woman who's been helping him. And he only has five days to find the truth.

I'm going to warn you now, there's a scene with someone's teeth being levered out with a claw hammer and one character doesn't keep his tongue all the way through. Plus someone eats a live octopus... The actual plot is a teensy-weensy bit implausible, but otherwise it's a very good film. Just opened in the US I believe, though currently available on DVD here in the UK.