On paper, he's the worst kind of villain: no solid backstory, no real motivation, no sympathetic qualities, no real grand-plan...
Batman's rogues gallery has some pretty damn sympathetic villains, yet the Joker is the one people seem to like the most.
WHY DO YOU THINK THIS IS, #OFFTOPIC?
-
He's unpredictable, insane and lives to torment batman for shits and giggles. I don't know hoe he escapes jail so easily though..Must have a inside man.