14. Sean Penn, 'Mystic River'
The first of Sean Penn's two Oscars this century came in Clint Eastwood's mournful Boston thriller. His portrayal of Jimmy, the ex-con hothead whose teen daughter is murdered, is knowingly melodramatic, full of high emotions and bubbling menace. (The scene where Jimmy learns of his child's death overflows with operatic anguish, probably cinching his Academy Award in the process.) Penn articulates every ounce of his character's anger and sorrow, making Jimmy both a tragic and ferocious figure. But it's more than a touch hammy as well, which undercuts the stark realism that Mystic River otherwise achieves.