Bruce Banner is not like Tony Stark, Thor, or Steve Rogers. Each one of the aforementioned characters are inseparable from their super hero identities. As Tony Stark said “I am Iron Man”. So because of this, the actor portraying each one these characters has a lot to do with the personality of that character. I firmly believe that no one can be Tony Stark other than RDJ. RDJ has infused his motor mouth wit coupled with his own dark history of drinking into a character that demands nothing less and has thereby branded his own personal stamp of ownership into the Iron Man armor. Chris Hemsworth doesn’t just look the part of Thor but has cemented a real sense of authority and honor into the god of thunder. We were all leery of Chris Evans as Captain America given his track record with other CBM’s but he managed to hit it out of the park by imbuing Steve Rogers with perseverance, selflessness, and tough as nails innocence. As for Bruce Banner, he’s no Dos Equis man. Can you honestly say that anything remarkable stood out about him between the 3 different actors that played him? I don’t think you can and I think that’s the way it is supposed to be. Banner is unremarkable, unassuming, and in control. For God sakes the man actively tries avoid stress and conflict…the very things that make any character interesting. While the Hulk is a demanding, out of control force of personal and urban destruction. The attractive tension between Banner and “the other guy” is that one is so boring that you probably wouldn’t notice him unless he bumped into you, while the other is so engaging that the world has no choice but to take notice. The Hulk and not Banner over stimulates our interest levels and that is why just about any male actor with talent and the appropriate age can play Bruce Banner.
I don't think I agree. The reason why the first Hulk (2003) film didn't do well is that I believe it was too cerebral. It attempted to introduce the Hulk as not a separate character but as an embodiment of part of Bruce Banner's psyche and anger that he had suppressed for so long including the the fall out of the memory of and emotion about the murder of his mother. So much so it was a multiple-personality disorder taken an exciting extreme. This was done very well in the comics of the 1990's but it just didn't seem to click for movie audiences. The 2008 version had a lot more action but definitely treated Hulk and Banner as separate entities but only hinted at more. In Avengers, I'd say that Banner had come far enough that he and the Hulk had come to a kind of acceptance of one another but still treated Hulk as "the Other Guy" - which still could fit the multiple personality disorder. I think both Norton and Raffalo did a fine job, but both brought a different take on Bruce Banner yet valid interpretations from the comics. Remember Bruce Banner is not an idiot, he is a genius. Both Edward Norton and Mark Raffalo managed to show that. I don't think any actor can pull that off. One things that made the Marvel brand of characters so unique with respect to the way genre was handled before was that non-superhero alter-ego was more important than the superhero. For example: Peter Parker is just as important character as Spider-man. It's the same with Bruce Banner. If Bruce Banner as a character fails, then so does the Hulk.
Can Anyone Play Dr. Bruce Banner? (Editorial)