Choi Min-sik — Oldboy
One of the many stunts in this movie involved the main character, played by Min-sik, eating a live octopus, and boy did he oblige. In fact, they had to do four separate takes so he ended up eating four. Since he is a Buddhist and a vegetarian, Min-sik apologized to the creature and said a prayer before he put each one in his mouth.
She was magnificent in that movie.