The beloved Muppets have been a cultural cornerstone on TV (The Muppet Show, 1976) and at the movies (The Muppets, 2011). ABC tried to take a stab at a more grown-up show for the cosy creatures, but the series, which featured Miss Piggy with a late-night show, got cancelled one season in. The adult, mockumentary style, so-so reviews, and underperforming numbers all contributed to its eventual doom. Looks like the Muppets didn't find the Rainbow Connection here.