(Just to make myself popular here with my 3rd post ) Peep Show
Firstly, I do like the show overall. Series 1 and 2 are superb (as in, "some of the best episodes of anything I've ever watched" superb), of my top 10 Peep Show episodes I think they'd all come from these two series with the exception of the wonderful Christmas episode. I find the rest very hit and miss in places. Series 8 and 9 were utterly woeful- They were continuing Peep Show as a brand, as an exercise, but on-screen it was going through the motions- the soul of the show had been sucked out. I can understand why it's a sacred cow when you consider it's contemporary competition but to me it had been on a slow death spiral of quality since at least the wedding arc was resolved, and that was back in series 4. It's a good show, at it's best it's a brilliant show, but goodness me did it outstay it's welcome, and for several years at that.
Only Fools and Horses
Similar to Peep Show, it seriously outstayed it's welcome and it's average quality as a franchise has suffered as a result. Almost all the '90s and beyond Christmas specials are a total non-starter to me. It feels like the premise of the show was killed off when they gave Del and Rodney romantic interests (not helped at all by the absolute lack of chemistry between Nicholas Lyndhurst and Gwyneth Strong) and it was a dead man walking once they played the dreaded "let's put a baby in this" card. Even then I don't think it's highs are that stellar. Again, I find it far more inconsistent in reality than it's reputation would suggest.
Mrs Brown's Boys
So utterly dreadful that the fact this isn't universally panned in every media outlet under the sun makes it "overrated". Unbearably bad.