Much like the infamous 1979 film debacle, Caligula is very likely to spark controversy on this list. He was just a Roman emperor after all, so how could I exclude Darth Vader but include Caligula? I smell hypocrisy! Don't get your panties in a twist, here's my reasoning: sure, Darth Vader killed many people and tried to kill his own children, but Caligula raped, sodomized, committed beastiality, assault, torture, killed his uncle with own hands, had his best friend's head cut off, and had another's penis removed from his body! And the infanticide, oh yes the infanticide! Caligula is as unpredictable as The Joker, but as powerful as a King... that's a deadly combination.