I would not have said The Jackie Gleason show, Baywatch, The Flying Nun and Hogan's Heroes were among the top 50 worst shows.  Otherwise I agree with pretty well all the others.
Although as a little kid I remember liking Manimal.  It was only seeing it in reruns years later did I realize how awful it was.
If this was a Canadian list it would no doubt place The Trouble With Tracey high 

The Tom Green Show?! I know he had his time in the spotlight in the early 2000s, but I remember watching his Rogers Cable show in Ottawa in the mid-90s. It was hilarious - of course, I was of an age to appreciate silly humour and pranks at the time. One show, part way through the episode, he took out a chainsaw and cut his desk in half 😄

It's a bit of a strange list and like a lot of these lists there's no particular rationale - it's largely subjective. There are also some sloppy picture selections - for example 48. Bless This House - is about the 1995  Andrew Dice Clay series from CBS but the picture is from the British series from the 70s starring Sid James - who looks nothing like Dice Clay. I don't know whose picture is accompanying #45 AKA Pablo but it's definitely not the show's star Paul Rodriguez. 

I agree about the Jackie Gleason Show - I assumed they must have been talking about You're In The Picture but no, it's the Gleason's entire 20 year run. You can certainly argued the show became tired and old-fashioned by the late 60s but when Gleason was at the top of his game in the 50s it really was a classic - at least from the reruns that one of the cable stations was running a few years ago and the material you can find on YouTube. And why go after Gleason and ignore Bob Hope whose TV specials continued for decades after they ceased to be funny or interesting (if they were ever that - I watched a few of this 1950s shows on one of the streamers and they were pretty bad. The only thing I've ever found Hope mildly amusing in is some of his Road pictures.