From Wikipedia's "List of Television Shows Considered the Worst"

Barney & Friends - One specific criticism is: "[H]is shows do not assist children in learning to deal with negative feelings and emotions. As one commentator puts it, the real danger from Barney is denial: the refusal to recognize the existence of unpleasant realities. For along with his steady diet of giggles and unconditional love, Barney offers our children a one-dimensional world where everyone must be happy and everything must be resolved right away."

Australia's Naughtiest Home Videos - The only known series in world television history to be canceled by its network midway through its first airing. Kerry Packer, Australian media magnate and owner of the broadcaster Nine Network, saw the show whilst out at dinner with friends, and reportedly phoned Nine central control personally, ordering them to "Get that shit off the air!" The network complied and immediately replaced it with reruns of Cheers, citing "technical difficulties." Packer arrived at the network the next day and again referred to the show as "disgusting and offensive shit." The show itself largely consisted of videos of animals having sex interspersed with off color jokes from the show's host. The show would not be seen in its entirety until 2008, three years after Packer's death.

Holmes & Yo-Yo (1976) - Holmes & Yo-Yo was universally panned by critics and is #33 on TV Guide's List of the 50 Worst TV Shows of All Time. Many Nielsen viewers claimed they felt "uncomfortable" with the show's often racy humor, most especially episode seven, over 14 minutes of which was Yo-Yo verbalizing (in graphic detail) his desire for genitalia. Although the series lasted only 13 episodes ... the influence of Holmes & Yo-Yo can be felt in other "robot cop" series and films that followed ... [including] Mann & Machine, which used the same premise as Holmes & Yo-Yo, only with a sexy female robot instead of the stout Yoyonovich.

The Swan - The show has been criticized for promoting plastic surgery, a view of beauty packaged and marketed by the fashion industry, and a lack of ethics in preying on vulnerable people. [USA Today] described it as "the most morally bankrupt TV since Al Qaeda's latest press release."

Who's Your Daddy? - For the show's premise, an adult who had been put up for adoption as an infant was placed in a room with 25 men, one of whom was his or her biological father. If the contestant could correctly pick out his or her father, the contestant would win $100,000. If he or she chose incorrectly, the person the contestant incorrectly selected would get the $100,000, although the contestant would still be reunited with his or her father.

Heil Honey I'm Home! - This UK sitcom depicted fictionalised versions of Adolf Hitler and Eva Braun living next to a stereotypical Jewish couple. The show was criticised for being unfunny and distasteful, and was cancelled after a single episode aired.

Cop Rock:



Also noteworthy: Homeboys in Outer Space, Galactica 1980, The Jay Leno Show.