Oldboy

A drunk nobody is snatched off the street and locked in a shabby private cell for fifteen years, fed the same fried dumplings, told nothing, then released as abruptly as he was taken and handed a few days to work out who did it and why. Park Chan-wook shoots the revenge as pop-operatic spectacle, most famously a side-scrolling corridor brawl done in one take with a claw hammer and a great many stuntmen. Choi Min-sik ate four live octopuses for one shot and, being Buddhist, apologised to each. It took the Grand Prix at Cannes from a jury chaired by Tarantino, and the ending is the reason nobody who has seen it will tell you the ending.