Frogprince mentioned Dylan as Alias in "The Ballad of Pat Garrett and Billy the Kid" as an especially bad performance and the movie as a garbled mess. I agree, but surprised he didn't mention Kris Kristofferson as Billy the Kid. Let me repeat: Kristofferson as Billy the Kid!?!?!? Not so much that the acting was so bad, but its the worst case of miscasting since John Wayne played Genghis Khan.
Billy The kid was 5'2" and died at 21. Kristofferson was 6'4" and 37 when he played the role. With a full beard even. The saving grace of the movie, besides Coburn as Garrett, was the scene where Slim Pickens lies dying in his woman's arms with the sun setting over a lake and Dylan's "Knocking on Heaven's Door" playing over the scene. How Peckinpah got that one scene so right and everything else so wrong is unfathomable.
    The best actor of the Beatles was Ringo.
    Check out Tom Waits in the Jim Jarmusch film "Down By Law".
    Spaw, thanks for the info about Alan Arkin. One more reason to respect one of my favorite actors. He once starred as Inspector Clouseau in the 1968 movie of the same name and was every bit as good as Peter Sellers who had a franchise with that character. His performance in last year's "Little Miss Sunshine" was sublime.