The Joker, only Heath Ledger's.
Mark Hamill in "Batman the Animated Series was pretty awesome.
Loki... you knew that was coming :)
Ernst Stavro Blofeld
Ben Linus from Lost.
The Joker in the Batman Comic Book World
Mr Tinkles .. The evil white person cast in the truth about cats and dogs
Oops Persian cat ... Not white person ... Sheesh I think I'm in trouble now