Deserve mention: Robert Mitchum as Rev. Powell, Night of the Hunter Mickey and Mallory Knox, Natural Born Killers Bill the Butcher, Gangs of New York Michael Rooker in Henry: Portrait of a Serial Killer ...and nobody has mentioned Norman Bates yet?
<iframe width="420" height="315" src="https://www.youtube.com/embed/wzbVn9Xx3YM" frameborder="0" allowfullscreen></iframe> Please don't boil my bunny rabbit.