I guess my issue is with the belief that somehow Heath Ledger did something so monumental with the Joker that no one else could have come close. I've not seen much of Ledger's work, but I am certainly impressed enough simply by the comparison of his Brokeback Mountain guy and his Joker. Entirely different voices, movements, attitudes, etc. Still, I think those other guys would have handled the role just fine, if differently. Ledger's death changes everything, and I offer as weird a comparison as you're likely to find: In 1951, Alfred Hitchcock made a movie called "Strangers on A Train," about a nice young man (Farley Granger) stalked and menaced by a mad young man (Robert Walker) who proves to be the nice young man's "crazed doppelganger." Robert Walker at the time was a player of light romantic comedy, with a boyish voice and manner. Hitchcock cast Walker "against type," and Walker gave an incredible performance, with a certain fey cracked flamboyance that was literally decades ahead of his time. (I'd say there is a fair amount of the Joker in the funny-yet-crazy madness of Walker's Bruno Anthony, and the Joker is a doppelganger, too.) But boyish Robert Walker had problems off screen. A mental breakdown. Failed marriages. Alcoholism. And barely a year after "Strangers on a Train" came out, Robert Walker died of a drug overdose in his early thirties, leaving his madman behind in "Strangers on a Train" as, literally, the performance of his life. It is still well regarded, today. Warner Brothers has a remake script for "Strangers on a Train" ready to go, and has been trying to make it for years. A few years ago, they announced who they wanted for the Robert Walker role: Heath Ledger.