In no particular order:
Colonel Kurtz, Apocalypse Now - The horror... the horror...
Tommy DeVito, Goodfellas - What do you mean I'm funny?
Hans Landa, Inglourious Basterds - Au revoir, Shosanna!
Max Cady, Cape Fear - The one with Robert De Niro - Counselor! Come out, come out, wherever you are!
Anton Chigurh, No Country for Old Men - What's the most you ever lost on a coin toss?