Lets see, On another website I played a Nazi Doctor. You know how that went. 
I've played Satan before. (Temporary.) 
I've roleplayed as a Paladin who started out pure, then just turned into this Tyrant who killed everyone. He had his own wife killed first. 
And finally, A Sociopathic horseman of the apocalypse. (Pestilence, Plague.) Who Didn't spread disease, but just shot everyone he met.