-- Joker in "The Killing Joke."
After spending some time in a forum where people were debating on which Joker origin story they prefer, I've come to a realization.
I don't want a Joker origin. I don't want to know where he came from or who he was before he was THE JOKER. The Joker transcends backstory. He's larger than life, larger than human. I think a comic author attempting to give him a backstory makes the same mistake as Harley Quinn did in "Mad Love" when she got suckered in by one of his phony sob stories about a traumatic childhood. She assumed she knew him, had found the "real" Joker behind the make-up, and what happened to her? Ouches, that's what. By making the Joker more "human," you rob him of the mythic quality that makes him so fascinating. You make him just another one of the Arkham-bound crowd. But he's more than the rest. One of my favorite parts of Ledger's Joker is the multiple fake backstories he throws around, because it doesn't matter which one is the true one-- because he's about to slice your face. I also loved the anonymity. No traceable fingerprints, no real name, no known anything. Just the way I like it.
In comics, Alan Moore and Brian Bolland also did it right in "The Killing Joke" (possibly the greatest Batman/Joker comic in existence). They provide a backstory-- in fact the whole comic revolves around this backstory-- but then they throw a twist at the end with the suggestion that even the Joker doesn't know if it's true! An awesome quote and extension of the one above:
Seriously, "The Killing Joke" is amazing in so many ways. Batman offers Joker one last chance to save them both from their mutually obsessive and suicidal course, telling him that he doesn't have to be alone anymore because he'll personally rehabilitate him (consequentially, the slashiest Batman/Joker moment to date), and there's this moment when the Joker-- Ah, just read it. You won't regret it.