The Bill Cosby Show

Some people write about this show "failing" because it was only on for a couple of years. My cloudy recollection is that it was doing OK, between 15-20 in the Nielsens, when Cosby went into one of his funks and quit doing the show. Can anyone verify this? Regardless, it was very, very funny. Character-driven, not gag-every-10-seconds-oriented like so many lame-brained sit-coms. The story lines were often imaginative: e.g. Chet Kincaid spending the whole show trying to replace a needle valve for blowing up basketballs; dealing with a potty-mouthed student and his parents; trying to borrow a vehicle for a big date (ends up driving a garbage truck). It often taught good lessons, but with subtlety compared to his '80s show.

The last time I saw it on the air was on Pat Robertson's old Family Channel over a dozen years ago. !?!?! Why have these re-runs completely disappeared?