10. Michael C. Hall
His eight-year stint as TV's most loved serial killer might make Mr. Hall an obvious pick, but there's a certain degree of similarly between Dexter and The Joker, other than their murderous ways. With his knowing fourth-wall-breaking voice-over, Dexter has always had a degree of wry humor to him - his low sardonic brow and ability to capture withering scorn in a single look don't seem too far away from The Joker's clapping mockery in the cells of Gotham Police Department. A veteran of the stage as well as screen, Hall has always had a degree of theatricality about him, too, such as in playing the almost literal puppet master villain in 2009's Gamer. Based on this clip, it's easy to imagine him gleefully wreaking havoc on the denizens of Batman's home city: His role as the Emcee in Sam Mendes' production of Cabaret displayed a similar almost sinister flamboyancy, though before Dexter he was best known as Michael, the deeply closeted elder son in HBO's Six Feet Under. All of this suggests that, most importantly, Hall is a hell of an actor. You don't receive 7 Emmy and 5 Golden Globe nominations (1 win) without some versatility. Hall would arguably make a better mastermind than agent of chaos (despite his claims to the contrary, Ledger's take on the character was most definitely a planner): he's yet to display outright insanity in anything he's done - is there any character, though, quite like The Joker - but he could definitely pull off a more matter-of-fact mayhem, running down pedestrians to torment Robin as in Paul Dini's Slayride or breaking out of jail to perform a series of executions as in The Joker's Five-Way Revenge. There may be a touch more Law Abiding Citizen to Michael C. Hall than Crown Prince of Crime, but, given Dexter is now in its final season, Snyder and Co. would be insane not to at least tap him up.