28. Lee Marvin, the Leatherneck
Lee Marvin dropped out of high school during WWII to join the Marines, then spent the next few years storming beaches. His courage was counterbalanced by orneriness and defiance of authority, so he kept bouncing through the ranks, getting promoted to corporal before getting busted back down to private. He was wounded in the Battle of Saipan, first by Japanese machine gun fire, then by a Japanese sniper who shot his foot. It took him a year to recover. After WWII, he moved to Hollywood, where his combat experience made him a sought after war consultant, and lent authenticity to his acting. He excelled in roughneck roles because he had been a roughneck in real life, with a mean streak that made his malevolent and tough guy characters ring true.