Lots of great comedy in this show, e.g. "I'm an ideas man Michael..." but I think my favourite moment of the whole show was when Henry Winkler did his Fonz style "ayyyyy" in the mirror.

He did of course also literally jump the shark, but the mirror gag was excellent as he'd been in a number of episodes (as I recall) before it happened so it was almost out of the "blue"...