Oldboy (2003)

Oh Dae-Su, an obnoxious drunk abducted on a rainy night in 1988, wakes up in a strange, windowless hotel room. Kept under lock and key for an unknown reason, Oh Dae-Su's invisible captors keep him fed and systematically sedated to avert suicide, providing only a colour television to keep him company. And after fifteen long years in captivity, perplexed Oh Dae-Su finds himself released. Now, his pitiless abductors encourage Oh Dae-Su to track down the ones behind the mysterious kidnapping and finally get his brutal, longed-for revenge on the unknown tormentor. However, who would hate Oh Dae-Su so much that he would deny him a quick and clean death?—Nick Riganas