3. When Things Were Rotten (1975)
Nobody even remembered this show once existed when it was turned into a feature film by its creator Mel Brook in 1993, under the revised title of "Robin Hood: Men in Tights". Which also didn't manage to find success but for different reasons; while the film just wasn't funny, the series was simply launched at the wrong time. American audiences, coming out of Vietnam and still recovering from the Peace & Love era as well as approaching the disco one, weren't in the market for the kind of absurdist comedy Brooks made famous with previous series Get Smart. If Mel had waited 4 more years, he would have found himself back in familiar territory as "Airplane!" split sides with a vengeance in theatres. Like Get Smart 10 years before, the series presented a satire of familiar material with a cast of characters entirely comprised of perfect morons. The show starred Brooks buddy Richard Gauthier as Robin Hood, surrounded by Dick Van Patten as Friar Tuck, Love Boats Bernie Kopell as Alan-a-Dale and Ron Rifkin (yes, THAT Ron Rifkin) as Prince John. Critics instantly loved it, yet audiences never showed up and cancellation followed after only 13 episodes.