Who were some of your favorite guest actors to appear in Happy Days episodes?

To start things off, I'll name a couple of mine: Buffalo Bob Smith and Linda Kaye Henning.

Apologies if this has been covered before (I got the idea from the Laverne & Shirley board).:)

Leon Askin !!!! Great Actor. Great Role. Great Episode :)

Buffalo Bob Smith, Howdy Doody and Clarabell

The Lone Ranger (John Hart)

Mork (Robin Williams) -- of course, he wasn't yet a star

Jack Dodson as Mickey Malph and Lorne Greene as ...HIMSELF!!!

Clint Howard - I think he was "Moose" wasn't he?

Tom Hanks in "A Little Case of Revenge."