Not sure whether it counts since I only watched it as a teen but I say MacGyver. A repetitive, formulaic one-man show with very irritating sidekicks (Jack Dalton, Penny Parker), laughably bad and/or ridiculous villains and often really boring plots. Yet Richard Dean Anderson and a (at the time) unique premise made this a hit show for 7 seasons. Must've been a lot of Patties and Selmas out there.
It seems like you may be judging a show for being full of 80s staples (repetitive plots, annoying sidekicks, ridiculous villains) because those things have gone out of style since. All of those things were common in the 80s and not seen as negatives. You also didn't need to be a "Patty" or "Selma" to like the show. It had wide appeal among both females
and males (I was one). I think that you need to judge a show by how good it was at the time that it was on. Recent shows that many consider to be the best on TV (ex. Game of Thrones, The Sopranos, The Wire, Lost) may seem laughably bad compared to TV shows in the 2040s, as well. That won't mean that they're bad shows, though, since that judgment ought to be based on the TV landscape that they aired during, IMO.
Saved by the Bell is probably #1, all time. Lord, I watched that show a lot growing up.
This is an honest question, but should we be listing shows that we watched and liked as kids? After all, how is it a bad show if it was targeted at the age range that we watched it during
and we liked it? It may seem totally stupid and awful to us nowadays, but it wasn't targeted at 30-somethings in 2017. It was targeted at teens and pre-teens in the 80s and 90s and was exactly what most of those of us then liked.