While Iron Man 3 was the highest-grossing movie of 2013, pulling in $1.2 billion, its leading man Robert Downey Jr. fell short of the No. 1 spot on Forbes' Top-Grossing Actors List. It seems the actor to acquire the No. 1 title earned it by simply working more. From Sandra Bullock to a few Fast & Furious stars, click the pics to see who tops this list.