Adrien Brody is a really good young actor in my opinion.
He was incredible in "The Pianist".
I first saw (or at least noticed) Brody in the Pianist, Watts in Mulholland Drive, and Black in School of Rock.
I went to see these movies not because I like to go to blockbusters, but because I like what I think are good movies. The thing in common with these movies is that they are both interesting and off the beaten path.
I suspect Peter Jackson is a movie fanatic of the Spielberg mold, and that he was looking at movies such as these for casting King Kong.
Here is what I think about everyone judging KK by its "Box Office Mojo" or whatever.
I suspect Jackson did not make King Kong for the money. I think he made it for himself and for his friends. Having seen it myself now, I think it's pretty good. The first 20 minutes alone are, I think, worth the price of admission in the way Jackson captures the feel of the Depression era (remarkable in my opinion because he's from New Zealand).
If Jackson had wanted to pick name brand actors and actresses, I imagine with the budget that he had, he could have and he would have. But you would not be watching the movie anymore, you would be watching the personalities. Can one imagine Tom Cruise as Jack Denham?
I am not saying it is a perfect movie. Jackson piled it on a little too much-- he could have slimmed it down a little more, held off on some of the special effects in favor of more character development. But that's a quibble. And anyway, I don't think he made the picture as much for the audience as for himself and his friends. That's OK with me-- I think he and his friends have pretty good taste in movies.