There have been a lot of iconic versions of The Joker, but one man made the Clown Prince of Crime a constant in the lives of fans for over two decades. That's Star Wars actor Mark Hamill, and after voicing the character in Batman: The Animated series, he would go on to also appear in countless other cartoons and video games. He even voiced The Joker in the live-action Birds of Prey pilot. Sadly, Batman: Arkham City was his final time as the villain, but Hamill actually tops Hugh Jackman's record of playing Wolverine for 15 years by having starred as The Joker in various forms for such a long period of time. There are many fans out there who would have loved to see him actually get to play The Joker for real, but the closest he's come to that is as the psychotic Trickster in The Flash TV series.
