Parent series: Friends
There are many reasons why most spin-offs are destined to fail, but if there's one classic mistake, it's this: Spin-offs or sequels routinely place the burden of lead on the shoulders of a fan favorite character from the ensemble or supporting cast that was simply not built to lead. There's a reason they kill every scene they're in: small doses. The comic relief in the sitcom or the foil in a drama is just one part of a larger machine. So why does every network make the fatal mistake of thinking that piece can run on its own?
Matt LeBlanc's dim-witted yet lovable paisan from the Friends gang embodies the Small Doses principle. The whole reason the original show worked for so long was that each of the six characters added up to one, at times flawless, whole. Really, none of them could have carried their own show, but boy was Joey the worst choice. Who thought audiences would be down to ride with the "How you doin'?" guy for a full half hour per week?
Maybe it could've been salvageable with a strong supporting cast, but even the likes of the great Drea de Matteo and Jennifer Coolidge couldn't turn the tin can into gold, word to Charlie Sheen. We're just amazed it actually got a second season.