If a living theatrical legend exists, it's Alvin Epstein. You may not have ever heard of him, but he's been a part of some of the most important theatre events of the last 50 years. He performed with Marcel Marceau back in the 50s, he played The Fool in Orson Welles' production of King Lear, played Lucky in the first American production of Waiting for Godot (with Bert Lahr and E.G. Marshall). Has acted and/or directed in dozens of important productions at the Yale Repertory Theatre and the American Repertory Theatre-- and at AGE 81, still continues to perform: currently appearing as the servant Firs in the Atlantic Theatre Co. production of The Cherry Orchard (and acting the rest of the cast off the stage)-- if you get a chance to see this man on stage, DO IT! This is what theatrical acting IS.
Let me also add to the list of legends: Directors Peter Brook, Ariane Mnouchkine, Garciela Danielle, Julie Taymor, Richard Foreman, Robert Wilson, and Ingmar Bergman (yes, he's still alive); playwrights John Guare, David Mamet, Sam Shepard and Caryl Churchill; The entire Wooster Group; and my favorite: Actor, Director, Writer, Choreographer, Historian, and (now) tony winner, BILL IRWIN
"Inside every actor there is a Tiger, a Pig, an Ass, and a Nightingale. You never know which one is going to show up."
-John Michael Higgins in FOR YOUR CONSIDERATION