But anyone playing a comic book character has the deck stacked against him (or her): (A) They have to be good enough actors to pull off the dual personalities described above. Who was the best? Probably Tobey Maguire: For the Solipsist's money, he WAS Peter Parker, and, since Spidey's personality is not too drastic an opposition to Peter's, he worked well in the costume as well. (B) Even when they ARE good actors, they are overshadowed--first by the high-tech moviemaking, and second--and more significantly--by the villains. Michael Keaton was fine; Jack Nicholson was memorable. Christian Bale was probably about the best one could hope for; Heath Ledger was scary. The filmmakers know this, too. Just think about how many times the villain has been a bigger star than the hero: Gene Hackman and, later, Kevin Spacey as Lex Luthor opposite a then unknown Christopher Reeve and a still unknown whatshisface (no, he doesn't even merit a Google lookup) as Superman. Sir Ian McKellen as Magneto vs. a then-unknown Hugh Jackman as Wolverine. (Yes, yes, Patrick Stewart was Professor X, but that's more like the Brando role, not the superhero. And the fact that a mega-star like Halle Berry was relegated to the second fiddle of Storm says more about racism and sexism in Hollywood than any number of Academy Award snubs). Eric Bana as the Hulk vs. Nick Nolte as. . . well, whatever his name was in the movie. Need we go on?
And why shouldn't this be the case? Let's face it, villains are more interesting. Be honest with yourselves, folks: If YOU had super powers, would you use them for good or evil? Maybe a little bit of both, but none of us would likely be as pure of heart as Superman. In an escapist medium, we identify more with villains, and filmmakers and movie stars know this. Maybe (MAYBE) deep down we want the hero to win, but while those two hours pass in the darkened theater, a tiny part of us wants to see the bad guy come out on top. And having the villain played by the name-above-the-title gives that tiny part something to cling to.
(PS: The single most terrifying comic book ever written, "Miracleman" by Alan Moore, is basically a disquisition on what would happen if Superman walked the earth--not for the faint of heart. For a cinematic taste of what this would be like, keep your fingers crossed that the upcoming "Watchmen" (another Moore project) is worth seeing.)