1. Oldboy (2003)
Tartan FilmsLoosely based on a Japanese manga series, the second installment in director Park Chan-wook's thematically-connected Vengeance Trilogy is not for the faint of heart. Oldboy blends elements of existentialism, film noir and Shakespearean tragedy to present a brutal, powerful and captivating tale of revenge that delivers a devastating third-act reveal. As a man imprisoned in solitary confinement for 15 years with no apparent reason before being released without explanation, Choi Min-sik is extraordinary in the lead role. Much has been said about the live octopus eating (which took four takes), but the actor's physical and emotional dedication to the character is nothing short of incredible. Directed with confidence, Park ratchets up the tension and suspense while also providing many visual flourishes, especially the brilliant single-take fight scene. A dark exploration of human behavior and the emotional power of revenge, Oldboy doesn't shy away from presenting the ugly side of human nature whether it be violence, torture or downright sadism. One of the great Eastern movies of the last few years, Oldboy deservedly landed the Grand Prix at the 2004 Cannes Film Festival.