Sam Rockwell remembers his favorite roles in a prolific Hollywood career

With over 80 screen credits to his name, Sam Rockwell has built a prolific career out of walking that fine line between character actor and leading man.

Some of his best work involves playing the strong supporting role in movies like "Galaxy Quest," "The Assassination of Jesse James by the Coward Robert Ford," and "Iron Man 2." But he's also fully capable of being the face of a film, in works like "Confessions of a Dangerous Mind," "The Winning Season," and "Moon."

With such a diverse filmography, we were curious what motivates Rockwell to take the parts he chooses. Here, he speaks candidly about three of them.