Mork & Mindy should have been just another contrivance of 1970s television—My Favorite Martian in Godspell Suspenders—but Robin Williams really was an alien in that world. Americans weren’t sure whether he was improvising his lines or channeling the voices in his head, but they wanted more, and he quickly parlayed his genius into a 35-year film career (captured in our photo gallery). While many of his roles were vehicles for his hyperkinetic comedy, he won critical acclaim for several dramatic roles, including his Oscar-winning turn in Good Will Hunting. The one constant in all Williams’ characters was an undertone of wistfulness. It was his quietest voice, but it might also have been his truest.