They share one quality that should be celebrated more often in our best performers. They all combine art and industry. Caine may have slowed down a bit since his hyperactive peak, but in this year's "Harry Brown" he showed he hadn't lost an iota of his potency. De Niro may descend to vehicles like "Little Fockers," but when he works for a director like Barry Levinson in "What Just Happened" or John Curran in "Stone," he can still rise to the occasion. And just this year, Damon made his presence felt not only in the exciting "Green Zone" and the engrossing "True Grit," but also as the narrator of the splendid documentary, "Inside Job." (Let me tactfully pass over "Hereafter.") Caine, De Niro and Damon all keep busy: they never let their acting muscles atrophy.