No one will ever do that Joker voice as well, so it's always going to be a shame. He was a much better actor than he ever got credit for. I definitely agree with that, too.
I've been re-watching "Batman: TAS" lately, and it's still astonishing to me the level of voice-acting talent they had on that show. I hope Conroy continues to do the voice, until such time as he sees fit to stop. That's another case of no one doing that voice (or voices, I guess) better.