Zeconte said:
Mind you, this is not the whimsical criminal prankster Joker of the more light-hearted portrayals of the Batman series, this is the psychotic spirit of anarchy and chaos Joker of the more mature and serious portrayals of the series.
The Joker in the more mature and serious portrayals of the series - for instance,
The Dark Knight Returns, as in the book rather than the movie - varies widely. In that particular book, however, he's nothing like Heath's character: he's calm, cool, collected, the epitome of the uncaring sociopath, not a fidgety anarchist out to prove something to the world. He just wants to play with Bats again. Like old times.
Heath's portrayal was definitely interesting, but like I said before, it just didn't seem like Joker to me. He was just some bat***t crazy guy with facial scars.
About the laugh contest above: I had to consider it for a bit, but I'm going with Hamill. Romero's got a convincing giggle, too, but it doesn't have quite the same sinister undercurrent Hamill puts into his that pushes it over from just laughter into okay-getting-creepy territory. Admittedly I liked the animated series more than the Adam West series, so I'm biased in that regard.