Tony Stark (Robert Downey Jr.) - Superheroes hide their real identities for all sorts of reasons -- maintaining privacy, protecting their loved ones, false modesty, etc. But for splashy billionaire business magnate and engineering genius Tony Stark, secrecy is for chumps. During a press conference regarding allegations that he is the mysterious armored hero, he initially denies the claims and laments, "I am not the superhero type." Instructed to only read from his cue cards, he continues, "The truth is..." pauses for a moment, and then boldly admits, "I am Iron Man." So much for media training.