Personally, I never understood people who say things like
"This actor was great in that scene in this movie, he would make a perfect [insert superhero/villain here]". Not that there's something wrong with it, of course, but it just doesn't seem as the right way to go. Just because someone played a smiliar/smilar role/roles before doesn't mean they would be the perfect choice for a superhero/villain.
Reminds me of some rumors a while ago about who was on the short list for playing Lex Luthor in a new Superman film, and they had listed several mediocre actors, all of which were just bald... That was it. Just a bunch of bald actors. Way to choose an actor for a role, just because he looks the part, or he looks exactly like one particular comic series version of a certain character.
I always prefer casting choices like the Heath Ledger/Joker one, Daniel Craig/Bond, Tom Hardy/Bane - ones that piss a lot of people off.

No, kidding - ones that make you wonder at first why they went with that particular actor. As long as the core of the character remains in tact, race, face, hair, even gender don't matter to me. I don't want to see Billy Zane as Lex Luthor for example, just because he resembles a certain picture of Lex. I want to see someone who can be challenged in the role he's been cast.