I really wish Chiklis could come back as The Thing. He was awesome. Also agreed on MCD as Kingpin, but disagree that the movie is that bad. Especially the Director's Cut, which is much better. I've said that dozens of times already on here, though.
A few of mine:
-ALL of the evil exes in Scott Pilgrim were perfect. In fact, everyone except Michael Cera were perfectly cast. Cera did a good enough job, but he was a very different Pilgrim from the comics.
-I'm surprised no one's mentioned Hugh Jackman as Wolverine. He looks and acts the part.
-Brandon Routh as Superman. Say what you will about Superman Returns, but he actually did a pretty outstanding job in the role for what he was given.
-Jackie Earle Haley as Rorschach in Watchmen. I might have personally disliked the film, but at least Rorschach was totally spot on from beginning to end.
-Alfred Molina as Doc Ock in Spider-Man 2. Nuff said.
And a few not so good:
-Pretty much the rest of the casting for Watchmen, especially Malin Akerman as Silk Spectre II.
-Ryan Reynolds as Green Lantern. He should've stuck with Deadpool and got that movie made.
-Jessica Alba as the Invisible Woman and Julian McMahon as Doctor Doom in the Fantastic Four movies. McMahon just wasn't the right actor for such a bombastic character and Alba was just wrong on every level.