Gotta give William Dafoe credit; he looked and acted exactly how I'd image Green Goblin to look and behave as a human...
Excellent acting performance on his part...
That said, I think Ledger was the better villian...
Joker had tremendous presence and some of the scenes with him were mind blowingly good...
Joker asking for his phone call (and the following mental manipulation of the veteran cop) and him burning all of that money was amazing...
IMHO, no villian was more polarizing than Ledgers Joker (and thats coming from a Future Sentinel fanatic)...
Joker, and I'm a huge Goblin fan. Dafoe did well, but he wasn't perfect. They could do better with Goblin IMO. So many tragic stories to adapt, and all they did was a malformed Death of Gwen Stacy story with MJ in which she survived. Goblin needs to be done better.
TDK Joker, on the other hand, was fking amazing.