This excellent and exhaustive MeFi post includes a wealth of links to some old National Lampoon recorded comedy bits, including the (to my mind unequalled) Mister Rogers spoof (with Christopher Guest!) that sent us all into hysterics when we listened clandestinely at Boy Scout camp 35 years ago.
Considering the era, this stuff was immensely transgressive comedy; take a while and sample. It’s fucking hilarious.