Re: Who deserves the most credit for MCU: Phase One success?
RDJ for making us all laugh and for bringing in new fans.
Favreau for what has been mentioned above (convincing Feige to let it happen)
Feige for letting/making it all happen
Whedon for tying it all together and for what he will inevitably do with the franchise
2014 Cinematic Adventures:
Noah | Captain America: The Winter Soldier | The Amazing Spider-Man 2 | Godzilla | X-Men: Days of Future Past | Dawn of the Planet of the Apes