Our favorite movie superheroes

Robert Downey Jr. has brought Tony Stark's Iron Man to life in 2008, the film's 2010 sequel and last year's "The Avengers." He's now back on the big screen in "Iron Man 3."

Robert Downey Jr. has brought Tony Stark's Iron Man to life in 2008, the film's 2010 sequel and last year's "The Avengers." He's now back on the big screen in "Iron Man 3."