Family Guy.
And I honestly never thought I would give that answer in a topic like this, because what's happened to the show is mind-blowing. Those original three seasons before the period of cancellation it had are still some of the funniest and most clever things I've ever seen, and while some of the negative things the show is known for are in them, they actually kept them in moderation, and also put actual effort into telling a coherent story and making the characters believable to some extent.
As far as I know, none of the original writers came back when the show was renewed (MacFarlane doesn't count; he only acts and produces all of his shows nowadays), and it really, REALLY shows. I was thrilled at the announcement, and I even found the first new episode of the season (The one involving Passion of the Christ 2) to be quite good. Then next week was horrible, but I just wrote it off as a fluke. Then the week after that. Then the week after that. Then the week after that.
Finally, it got to the point where a season had ended. I looked back and realized that because of my devotion to the old episodes, I had sat through a bunch of garbage. At that point, I only watched occasionally, and eventually I just gave up. Nowadays, he only recent episodes I've seen were Road to The Multiverse and the first Star Wars episode because people online were absolutely raving about them, but I walked away finding them to still be crap and in terms of their concepts, wasted potential.
Okay, I take that back. I did just watch Brian's Got A Brand New Bag on Hulu after checking out the TVTropes Family Guy Dethroning page (Where people post their opinion on when the show pretty much jumped the shark) because I couldn't believe the stupid things I read about the episode and wanted to see if it was really that bad. It was, and when I read the little reviews for the episode on this board I was stunned to see people loved it.
If you're wondering WHY I hate the new Family Guy, where do I start?
- Offensive humor that seems to be there only to be offensive. Not only does that get old fast, but there is so much more racial humor thrown in than any of the other seasons- Hell, even any other SHOW, including stuff like Drawn Together and South Park- that it gets to the point where I'm worried that some of the people behind this really do feel that way, and are getting away with it and becoming rich all in the name of comedy. They have nonstop jokes about Mexicans being poor. They have nonstop jokes about Asians having tiny genitals and breasts (Not to mention out of nowhere Peter starts talking about having sex with an Asian girl and fantasizing about it for half a minute in the middle of a speech). Oddly enough, I don't remember seeing as many jokes targeted as blacks as these others.
- Plots that are just dumb. I noticed this in Petarded, where Peter really starts messing with the family, eventually resulting in Lois getting covered in boiling french fry oil and being in a full-body cast at the hospital. Then Peter's at home sulking, he opens the door, and...There's the whole family, with a perfectly healed Lois (No explanation given), who forgives him for no reason. Also, go look at a synopsis or watch the episode McStroke- Often shows like Family Guy and Simpsons have a set up in the first act that leads into a different plot, but the first plot in this TAKES UP AT LEAST HALF THE EPISODE. The shift is jarring, and the resulting plot is ludicrous- Peter wants to bring down the fast food company that allowed him to eat 200 burgers and have a stroke (Because apparently that's their fault), and finds a talking cow (?) that can describe how they treat their cattle. They go out of business and Peter's a hero. WHAT?!
- The main cast has been ruined. Brian has gone from a straight man to an avatar for whatever social issue the writers want to talk about. They devote an episode to show Brian proving that God doesn't exist and religous people are idiots. They devote an episode to Brian arguing that pot should be legalized. As for other characters, Peter has gone from a stupid but good-hearted guy to a maniac who beats up random people (including his kids), Lois has gone from another sort of straight man to a sex maniac who cheats on her husband, berates her kids, and so on. Stewie is mostly unchanged, but Chris and Meg are almost nonexistent in the big picture now. And don't get me started on the Meg-bashing jokes- It's not that I feel so sorry for her so much as that they are just running the same basic joke into the ground- not to mention that it's really strange that the family appreciated her to some extent in the old seasons (There were bashing jokes then, but they were less frequent and much funnier as a result) and went to finding her a waste of life between seasons with no explanation.
Wow, I've typed a lot. I'll add some more in another post tomorrow.