If you like vintage comedy (
It's a Mad, Mad, Mad, Mad World, The Producers, etc.) I can heartily recommend
Something Funny Happened On The Way To The Forum from 1966. It features late-but-great comedy gold: Zero Mostel, Phil Silvers, Jack Gilford, slient-film icon Buster Keaton (his final film) and many well-known Brits in other roles. Songs by Stephen Sondheim. I really admire the sharp script and excellent comedic timing of the performers. It was originally a play that did over 900+ performances, and then worked into a feature film.
Stream it here: