I know I've seen him numerous times, but the only one I can put a pin in is Brubaker. Was he the guy who ripped a toilet out of the jail, resulting in his third strike?
The perfect character actor. I knew his face but no idea what his name was. Vincent Schiavelli and Stephen Tobolowsky are two more I had to look up because they might have just a few scenes but their presence adds so much to the films they're in.
EDIT: He was the bartender in Back To The Future, Part 3? Well, I'll be damned.