Wikipedia: "Sometimes a television series is successful, and goes on to become well-known. Other shows are canceled shortly after their first airing. Rarely, a show is canceled after (or during) their first airing, and never given a second airing; these rarities are the subject of this list."

Ever heard of Who's Your Daddy? :
"2005 reality series on Fox TV that involved an adopted woman trying to pick her biological father out of a group of imposters. The show attracted protest from adoptive families and adoption-rights groups before airing. This combined with the fact that the first episode had poor ratings caused the five additional episodes to be permanently shelved."