A few years ago I was thrilled to find a DVD compilation of childhood favorite The Electric Company. You can read a bit about it — and in particular its crossovers with predecessor Sesame Street — on the Muppet Wiki, as well as in greater depth on Wikipedia.
I have fond memories of the show, from Rita Moreno's familiar opening shout to the animated Adventures of Letterman shorts to Morgan Freeman as Easy Reader to Skip Hinnant in Fargo North, Decoder, to — of course — the strangely silent Spider-Man
(on which more another time). What surprised me when I popped in the DVD was how much was unfamiliar, including the delightfully absurd soap-opera parody Love of Chair. The first episode of the serial is up on YouTube, albeit bootlegged; just when you think it's started running on fumes about two-thirds of the way through, it finishes with a couple of laugh-out-loud moments. Some interesting but spoilery trivia follows in the comments section below.
Screencap © 1971 Children's Television Workshop.