Screen presence – and a strategically placed bath towel – helped boost actor Eric Dane from likable guest actor to a recurring character with plenty of arduous fan support on the popular series “Grey’s Anatomy” (ABC, 2004-). But his turn on “Grey’s” – as plastic surgeon Dr. Mark Sloan, dubbed “McSteamy” by the appreciative female staff of Seattle Grace Hospital – was not the first time his chiseled good looks had earned him the rapt attention of viewers. In fact, Dane had been building a solid list of credits on television, and to a lesser extent, motion pictures, since his acting debut in