Iron Man: B-list no more

We have the movies to thank in making Iron Man a popular mainstream superhero.  Prior to the movies, only comic book fans know about Tony Stark, his secret identity, his millions (billions?), his womanizing, and his bouts with alcoholism.  Another, more popular superhero in similar situation is Bruce Wayne, aka, Batman.  But many more know about Batman than they do Iron Man.
Batman vs Ironman
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Not the case anymore since Robert Downey Jr. did an amazing job introducing Tony Stark to the world.  Iron Man went from the B-list to the A-list. 

Though I don't recall who was the fan favorite to play Iron Man when the movie was first announced, RDJ did not immediately come up.  In my mind, prior to RDJ's portrayal, the best Iron Man would be Tom Seleck in his 30s to 40s.  But that's all in the past.  Robert Downey Jr. will forever be Iron Man in many fans' minds.  He owns that role.

Here's a dilemma, now that there's an Avengers movie coming out, should Tony Stark, played by Robert Downey, be the leader of the Avengers?  It's just practicality for me.  I believe that more people, especially the non-diehard fans of the comic books, would rather see more screen time of RDJ than Chris Evans who plays Captain America.