4. I SAW THE DEVIL (2011)

The Chaser on steroids? Starring Korean superstars Lee Byung-hun and Choi Min-sik, this revenge thriller could’ve wrapped up after the 30-minute mark, since the main protagonist captures the villain without much effort.

Having your fiancee killed gruesomely by a serial killer must be one of the most traumatizing experiences in your life, but instead of clocking his prized enemy in the dome with a stone, the now-single guy lets the killer live. Why? So he can repeatedly catch him and beat the shit out of him again and again.

His tactics include ripping one of the killer's friend's mouth open with his bare hand, slicing open the killer's Achilles tendon, and smashing an eye with a dumbbell. You got to love dude's creativity.