And the voice of Milton The Toaster in the old Pop-Tarts commercials!I'm surprised no one's mentioned William Schallert. Patty Duke, Dobie Gillis, Star Trek, The Partridge Family, many other guest roles.
Some others--Sid Melton (Danny's agent on "Make Room For Daddy", con man Friendly Freddy on "Gomer Pyle", and Alf Monroe on "Green Acres"), which nicely segues into Mary Grace Canfield (Mary Grace on "The Andy Griffith Show" and Alf's sister Ralph)
Someone mentioned Virginia Gregg...She was one of the, to borrow a phrase, "Mighty Dragnet Art Players" who popped up on that show from time to time along with Anthony Eisley and the guy (can't remember his name) who played the con man posing as a forest ranger.