Pretty straightforward question. Who is your favorite? Personally, I think they all did good jobs within the context of their respective media. For me, I have to go with Ledger. His performance was legendary and gave a lot of depth, complexity, and layering to the character. Second would be Hammill. He did so much with just his voice. I also have to give an honorable mention to Nicholson. It's easy to write off his performance because of the film itself. But he actually did justice to the character. Another honorable mention to Zach Galifianakis' Joker in the Lego Batman Movie.