The Naughty Nineties, while it does not deviate from the Abbott and Costello formula that had been firmly established by 1945, is nevertheless one of the duo's best efforts. Once things get going (after a slow start), they never relent -- one funny comic sketch follows another, right up until the madcap finale. There's also the old stand-by, the "Who's On First?" routine. It had been done before and would be done again; I've heard it many times myself. Somehow, it's funny every time.