Funny / Saturday Night Live
"Guess what? I got a fever! And the only prescription is MORE COWBELL!"

Saturday Night Live is a sketch comedy show that, despite its near-constant changing of cast members and writers and occasional dips in quality (often due to the aforementioned cast and writer changes), has remained on NBC for almost 40 years (completed 40 seasons and is about to complete its 41st). And it stayed around for two reasons: 1) NBC didn't want to lose the show, even in the early-to-mid 1980s when it always seemed to be teetering on the brink of cancellation, and 2) because, even at its lowest point, it still turns out some memorably funny moments (your mileage may vary, of course).