What is the worst TV show decay you've seen?

I mean shows that started well and decayed into horrible shows. I actually don’t mean shows that had a bad finale, but were otherwise OK. What shows degraded the sharpest in your experience? My list is below, though in no real order:

  1. Heroes - Great show in season 1. Terrible from then on. A genuine drop from greatness to horribleness. So weird. Night and Day. No idea how that happened.

  2. Nikita - A shocking choice, but a serious one. I like this show a lot, but my wife and I skipped tons of episodes at the end just to put this out of its misery. We hated it later on. When main dude lost his hand and got it back again, I could not roll my eyes enough.

  3. X-files - Only because they continued to season 8 and 9. I love season 10 so far, though. It’s weird there are two seasons no one cares about. There are about 3 good episodes in the entire 8th and 9th season.

  4. The Simpsons - Hardly worth mentioning. Classic to just a show that has hundreds of episodes I’ve never bothered with. I can’t believe it is still on.

I know there are many more. I did not list Twin Peaks, as I think a lot of its later shows were really good, even post killer-reveal. I like LOST and Battlestar all the way through, even liking their endings. I like Babylon 5 enough to ignore its mixed early season 5.

What else had declined/degraded?

Community

Dexter. Compelling through the John Lithgow season, then just got worse and worse with every season.

Yeah, Heroes is the only one that immediately springs to mind. Its decline was so weird given how awesome the first season was; it’s almost as if it became an entirely different series when season two started. I stopped watching midway through season three and never went back to it.

Apparently Heroes Reborn was nothing short of mediocre as well. That wasn’t renewed, so I can only assume that Heroes is well and truly dead now.

LOST is a strange one because it endeared me throughout its entire run only to piss me off so much by its ending that I kind of look back poorly on the rest of the show in retrospect. Some of its episodes are still damn fine television, though; for example, “The Constant” is probably one of the best episodes of ANY television show ever made.

But yeah, its ending sucked, so in that sense the show declined.

Dexter really fell apart in the last season. As I recall it seemed like the writers just didn’t care anymore and the finale was terrible.

The Office, IMO, went from one of the best shows on at the time to mediocre after The Michael Scott Paper Company opened up.

Roseanne was pretty decent until they hit the lottery, then the show hit the skids.

Grace Under Fire–no surprise there, Brett Butler was practically incoherent the last season. Drugs and booze will do that to you, I hear.

Downton Abbey. I really liked the first two seasons, but it went sharply downhill in the third season and I stopped watching after that.

Homeland. Had one of the most incredible first seasons I’ve ever seen, but the second and third seasons were pretty disappointing. I’d say the quality has rebounded slightly since then, but I doubt it will ever approach the first season suspense.

True Detective. The first season, while not perfect, was some very, very good television. Sharply written, compelling, well acted, and visually interesting (the six-minute single tracking shot was a standout, but it was really beautiful start to finish).

The second season was utterly unwatchable, top to bottom. Terrible dialog, mediocre acting, impenetrable story, and late-night Cinemax erotic thriller level cinematography.

The original British version of Shameless was really great to start with but cast attrition happened every year and by the end it was unrecognizeable.

Heroes is a good one.

Ally McBeal went from one of my favorite shows to completely unwatchable.

L & O SVU: after Olivia became the boss and it seemed every episode was abt her tortured personal life. Meh, hijacks turned it from the crisp police procedural to a Lifetime movie of the week. Ditto on Roseanne - whacked out shit aftr lottery.

The first three seasons of Farscape are among the best space opera shows ever to be on TV. The fourth season is complete crap.

Arrested Development: Amazing show during it’s original run…utter crap during the reboot.

Two shows that only had two seasons. Great first seasons, interesting premises, awful second seasons and inevitable cancellation.

Life with Damian Lewis

and

Eli Stone with Jonny Lee Miller.

And Intervention: is there anyone on Earth who believes they’re in “a documentary abt addiction”?? And why they’re asked to appear at a Red Lion conference suite? Dexter: couldn’t hack the gorefest it became.

Futurama. The original run was great. The four movie things they did were mostly crap, though still better than most of all of television. Then the final run was better and then crap again.

Glee went swiftly from “Funny subversive high school comedy with music” to a string of Very Special Episodes and iTunes commercials.

Last season of Star Trek TOS
Brain! Brain! Brain! What is brain?

Roddenberry didn’t care anymore and I assume the budget was cut

Jim’s Son–that would make you Morg, not Eymorg.

Sheesh! And that was only the first episode of that season.

What might be one of the quickest: Studio 60 had an amazing pilot and almost immediately fell off a cliff.