The "Four Yorkshiremen" sketch from Monty Python Live at the Hollywood Bowl:
I was not aware until searching for this at YouTube, but the sketch actually predated Monty Python's Flying Circus.
From At Last the 1948 Show:
Last, but not least, here's Eddie Izzard, Alan Rickman, Harry Enfield and Vic Reeves performing the sketch in 2001 in a concert for Amnesty International:
Thus endeth today's lesson in Python history.