Tony Stark Reigns Supreme
Nick Fury's first choice to lead "The Avengers Initiative" was our chance to be amazed by superheroes again. Marvel had trouble setting its footing after a few missteps (Eric Bana, anyone?) and Iron Man looked to change the climate. Blending comic book canon with the star power of Robert Downey, Jr., Marvel had an instant hit and we had a leader to take comic book movies into a rejuvenated direction.
Even if you didn't know what was going on (I mean, how many caught Cap's shield Easter egg?), Tony did and thought about the next five moves after that. That type of foresight is why Iron Man will continuously be one of the first films to come to mind when the "Best Marvel Film" debates begin.