1. The Joker
He may not have taken over the world and it's true that he couldn't hack it in a battle against someone like Superman, but when it comes to sheer villainy, who better personifies that than The Joker? Whether it's Death in the Family, The Killing Joke, or even his recent appearances in The New 52, the Clown Prince of Crime has committed a long list of twisted and despicable acts, singling himself out as Batman's greatest enemy and a bad guy who is perhaps more evil than every other character listed here combined. The Joker may be insane, but when it comes to making the Dark Knight's life a living hell, he knows exactly what he's doing. Which other DC villains deserve to be on this list? Share your favourites below in the comments thread.