Even the most die-hard fans of these TV shows will have to it that there came a point where they just went downhill. Not every TV show can appear on the list of the greatest TV shows ever. It's too impressive a list to include every single one. However, what can be incredibly frustrating is when there's a show that seems like it should be on the list of best TV shows ever, but its downward spiral keeps it off, or lower than it ought to be. Some shows can keep the quality consistent, and others stumble and fall.

It can be a frustrating experience, watching a show you once loved steadily go downhill and knowing that there is no real way back. Sometimes a show starts off with an incredible first season, then flops, like in the case of Heroes. Sometimes, a series just peters out, like The Walking Dead. The worst case of this comes with shows that are great for two or more seasons, and then one season comes along that sends things into a tailspin. You can see it coming in some cases, but in others, it's a disappointing surprise.

9 House Of Cards (2013-2018)

Began To Go Downhill In Season

The first two seasons of House of Cards were extremely exciting. Watching the now-disgraced Kevin Spacey work the levers of the American political system, and bring the viewer along for the ride with his fourth-wall breaks, was thrilling, funny, and endlessly entertaining. All his work culminates in the finale of season 2, where he victoriously stands behind the desk in the Oval Office and gives it two raps with his knuckle, a signature, before the show cuts to black.

Then the series keeps going, and we were given a crash course on why it's a bad idea to give a character exactly what they want so early in a show's life cycle. Frank Underwood is a much less compelling character when he's not striving. As president, he got what he wanted, and now wants to retain power, which means doing things that are actually popular, so he's no longer that conniving or evil. Once Frank leaves the show, House of Cards is barely the same series it was when it started.

8 The Umbrella Academy (2019-2024)

Began To Go Downhill In Season 3

The Umbrella Academy, based on the comic book of the same name by Gerard Way, revolves around a dysfunctional family of adopted superheroes who reunite for their father's funeral, which signals the beginning of the apocalypse. The first two seasons are inventive and imaginative, with each character getting plenty of time to be fleshed out. It's a dour show, but it's balanced out by the emotional storytelling and dazzling superhero aspects.

In season 3, The Umbrella Academy sped up its storytelling, and it became clear the showrunners were trying to get to an ending in two seasons, a tall order for how much was left to tell. The dialogue that was once interesting and natural suddenly became clunky and boring. It's a convoluted final two seasons of the show, and it's a big dip in quality for the series.

7 Once Upon A Time (2011-2018)

Began To Go Downhill In Season 4

Once Upon a Time was an exciting prospect upon its premiere. A TV show on the Disney-owned ABC with access to the vast library of Disney movies, Once Upon a Time brought age-old fantasy stories to life well before the Disney live-action boom began in earnest. For the first three seasons, Once Upon a Time was a magical series with a clear story to tell.

However, beginning in season 4, the show started to falter. While characters from Disney shows were always a part of the series, they were also characters from folklore and public domain fairy tales, which made the series feel less beholden to Disney itself. In later seasons, however, characters like Elsa from Frozen became important to the story. What was worse was that the plotting became overly complex and the dialogue stilted, resulting in the series losing a lot of its magic.

6 Weeds (2005-2012)

Began To Go Downhill In Season 4

Weeds was Breaking Bad before Breaking Bad. The show follows Nancy Botwin (Mary-Louise Parker), a widowed mother who begins selling marijuana to her family. Ostensibly a dark comedy about a suburban mom getting involved with the illegal sale of drugs, the series became more dramatic and intense as the series went on, and Nancy became more entwined in illegal activities.

This all came to a head at the end of Weeds season 3 when Nancy burned her house down and moved closer to Mexico in season 4. This decision completely altered the trajectory of the show, and it went from a series about the juxtaposition of mundane modern life and criminal activity to a show just about criminal activity. It was no longer unique and lost an important part of its individuality.

5 Glee (2009-2015)

Began To Go Downhill In Season 4

The hit musical comedy drama Glee was massive the first three seasons it premiered. The satirical look at a glee club is hilarious and smart, and pokes fun at many of the classic teen sitcoms of the era, while still providing an interesting dramatic storyline. The jukebox musical numbers are all well done and a lot of fun to go back and listen to, and the ensemble cast was particularly talented, both as actors and singers.

However, even the biggest Glee fans would it that the show entered a downward spiral in season 4.

However, even the biggest Glee fans would it that the show entered a downward spiral in season 4. Season 4 introduced a new group of characters to the Glee cast, but still tried to include storylines of graduates who were working and studying in New York. This resulted in too many storylines, and the series lacked focus. Suddenly, Glee started to feel like those teen drama series it was originally satirizing.

4 Sherlock (2010-2017)

Began To Go Downhill In Season 3

Sherlock is a modern interpretation of the Sherlock Holmes story by Arthur Conan Doyle and stars Benedict Cumberbatch as the titular detective. The series, which ran for four seasons, was nominated for a Golden Globe and 15 Emmys, winning four times. For the first two seasons, the series was a smart and unique take on the classic story, and Holmes is presented as a cold and analytical inspector.

However, in season 3, the series follows up on an incredible season 2 finale in which Holmes faked his own death, with an unsatisfying explanation that didn't make much sense. That became the order of the day for Sherlock. The writing just got worse over the next two seasons; cases became more convoluted, and audiences had to suspend their disbelief to untenable levels.

3 Dexter (2006-2013)

Began To Go Downhill In Season 5

The first four seasons of Dexter are some of the best that HBO and crime dramas have to offer. The story of a serial killer who silences his urges by only killing other murderers is an excellent premise, and Michael C. Hall's portrayal of the titular character is incredible. Those first seasons feature some truly thrilling storytelling, and the character development throughout is as good as any. It's in season 5 where things start to wobble.

Dexter: New Blood premiered in 2021 as a continuation of the original series.

Dexter becomes much less intelligent over the seasons, making mistakes he never would have before. The crimes and stories are much less clever as well, and twists are telegraphed. One of the worst decisions was to have Dexter and Deb (Jennifer Carpenter) fall in love, a choice decried by fans, and the finale of the series stands as one of the most disappointing finales ever.

2 Game Of Thrones (2011-2019)

Began To Go Downhill In Season 5

Game of Thrones may be on the list of the best shows ever for some, but it should have been nearer to the top. Unfortunately, the last four seasons of the show, and in particular the last two, completely blew its chance of being ed for the highs it once offered. Based on George R. R. Martin's unfinished series, A Song of Ice and Fire, Game of Thrones was a phenomenon when it was on, with incredible twists, fantastic world-building, and a storyline that appeared to be heading for something grand.

Then the wheels fell off in season 5, and characters who once seemed intelligent started making mistake after mistake. Plots were condensed, characters gained unheard-of amounts of plot armor, and the show ended with a finale that was disappointing in just about every way. Even going back to the series can be tough, knowing what's to come.

1 The Simpsons (1989-Present)

Began To Go Downhill In Season 11

It can be painful for some fans to it their shows are going downhill, but with The Simpsons, it's more a question of when than if. Even the true lovers of the animated series have to it it's nowhere near as good after 36 seasons. That's not even necessarily the show's fault; it's hard for anything to be quality for that long. However, for those who have been around the longest, season 11 is about the agreed-upon time when the quality notably started to dip.

Season 11 includes two of the most reviled episodes in the show's history: episode 13, "Saddlesore Galactica", and episode 19, "Kill the Alligator and Run". While some late episodes might be considered "worse", these two introduced aspects that became a part of the show forever after, and not for the better: absurd and fantastical storylines and celebrity cameos for the sake of celebrity cameos. The Simpsons is a landmark of television, but every TV show, if it goes on long enough, would probably go downhill.