There's a moment in Pulp Fiction where Samuel L. Jackson explains to John Travolta how TV shows get made, saying
"Well, the way they pick TV shows is, they make one show. That show's called a pilot. Then they show that one show to the people who pick shows, and on the strength of that one show they decide if they want to make more shows. Some get chosen and become television programs. Some don't, become nothing."
In the case of these absolutely nuts 10 shows, they're the ones that became nothing.
It was meant as a much racier version of the popular sketch comedy show Laugh-In, but it was apparently too racy for both audiences and networks in 1969. One station didn't cut back to the show after the first commercial break, while several others refused to air it at all, making it the only show to be canceled before the first episode even finished!
The Melting Pot (1975)
Spike Milligan was an immensely influential TV comedian (he's often considered the inspiration for Monty Python's Flying Circus) and he had a string of successes with shows that were both funny and also socially conscious. The Melting Pot, where he starred as a Pakistani immigrant (complete with dark makeup, yeah) dealing with racism in Britain, was not one of them.
Co-Ed Fever (1979)
Thanks to the success of "frat-house" movies like Animal House, CBS tried to cash in on the trend with Co-Ed Fever. However, only one episode was ever shown in a "special preview" timeslot, and ratings were so low that the rest of the produced episodes were never broadcast.
Comedian Melba Moore was all set to star in a new sitcom named after her, but the morning it was supposed to air, the Space Shuttle Challenger exploded above Cape Canaveral. The nation was in mourning, and Melba was toast.
It seriously only gets crazier from here...
Heil Honey, I'm Home (1990)
Possibly the single stupidest idea for a sitcom ever, Heil Honey, I'm Home was a British sitcom spoof in which Adolf Hitler and Eva Braun go about their lives while being unable to get along with their Jewish neighbors. We're not surprised it got canceled after a single episode; we're more surprised that it even got that far.
South of Sunset (1993)
When private detective shows were the big thing on TV, CBS produced one starring Glenn Frey, best known as the primary singer/songwriter of The Eagles. It was heavily promoted during the 1993 World Series of Baseball, but when it came time to air, it was pre-empted by mass news coverage of a wildfire outbreak in Malibu. The network canceled the show without ever really giving it a chance.
Brian "the Boz" Bosworth was an NFL player whose draft lead to a short career of injuries and controversy. He followed this up with repeated attempts at an acting career, which lead to his appearance as motorcycle-riding private-eye John Lawless (no, we are not kidding). Suffice to say it didn't make it past the first episode.
Comedians Unleashed (2002)
Animal Planet has made several attempts at having original programming that wasn't just nature documentaries. Some have been successful, but a standup comedy show featuring entirely jokes about animals probably wasn't the best idea. It did feature a young Chris D'Elia though!
The Will (2005)
Reality TV shows are infamous for having some pretty sketchy premises at times, but this one was too much even for most. The Will had a real-life millionaire getting his friends and family to compete to inherit his money and expensive ranch. Viewers were not impressed, and complained en masse to the network.
Emily's Reasons Why Not (2006)
Fresh off her run in a string of successful movies, Heather Graham signed on to this sitcom that was highly reminiscent of the immensely successful Sex in the City. Unfortunately, the show suffered from awful writing and some pretty offensive gay stereotypes, and was cancelled nearly immediately. Apparently the network had approved it without watching the pilot.