11. Jeremy Piven
Fans know Piven as Ari Gold on the HBO series “Entourage,” but his first big break was Jerry Capen, a fictional writer on “The Larry Sanders Show.” In a twist of irony, on “Entourage,” Piven’s character was a powerful Hollywood agent. One of his clients was Jeffrey Tambor, who played himself on “Entourage.” Piven continues to act, mostly in television these days.