Kevin Dillon

Biography: After being discovered by an agent at the opening of his older brother Matt's 1982 film Tex, Dillon landed a succession of high-profile supporting film roles, usually playing out-of-control teens (a prankster in Heaven Help Us, a trigger-happy soldier in Platoon). In the '90s the prolific actor appeared in numerous films, although their quality could be easily determined by his billing: If he was the star (Misbegotten, Hidden Agenda), it was a B-movie. As the decade wore on, he turned his attention to TV, with recurring roles on NYPD Blue and 24. Then, in a classic case of art imitating life, Dillon signed on to Entourage as the less-famous brother of an up-and-coming Hollywood star. At once pompous, egocentric and completely insecure, Dillon's hilarious characterization revitalized his career, earning him Emmy nominations, and often stole the show.