6. The Joker
"Do you want to know why I use a knife? Guns are too quick. You cant savor all the little emotions. In you see, in their last moments, people show you who they really are. So in a way, I know your friends better than you ever did." It doesn't matter which version you go for, the Joker was, and he will always be, one troubled sociopath. In Batman, he was a regular gangster who just had a very bad encounter with the Batman, and after going through a very long and painful surgery only to see him as a monster, he lost his mind. He became the Batman's first big foe and actually gave him a very big and serious trouble. Jack Nicholson's excellent performance showed him as a murdering sociopath with only one goal: to destroy Gotham City. Heath Ledger's Joker on the other hand is a completely different take on the character. We don't know who he is, or who he was. What happened to him? Why he is insane? What kind of horror happened to him in order to become such a monster? He could have been a guy just like you or me, maybe he was already a madman from the beginning. That kind of mistery actually helps the character, because it makes him completely unpredictable. So when he actually executes his plan, nobody is ready for the storm that was coming to Gotham. A character that will be remembered for many years to come.