Heroes, the biggest drop in quality after season 1. -u/scruntyboon

The Walking Dead. First few seasons were great with pretty good pacing. Later seasons devolve into telling one story at a time. They’d have a cliffhanger of a character maybe dying and do 3 weeks of other stories. By the time it gets back to the cliffhanger you have no idea what’s happening. That and it got repetitive. -u/THE_BANANA_SHOW

The Chilling Adventures of Sabrina. It was really cool. Then later on....Jesus Christ, the protagonist is a mary sue, everyone always listens to her, you can always guarantee none of her friends will die and you can always feel like the trouble she gets herself and her friends into aren't threatening. What a waste. -u/FleshOrb

The Blacklist, so many loopholes and a never-ending plot. I mean, the female hero was wanted and had her pictures broadcast nationwide live, but a couple of weeks after she can do undercover work. -u/TheReal_KindStranger

Arrow. It's what happens when you try to make so many seasons for a show meant for only a few. -u/MiZe97

Castle. By the end of filming the two main leads hated each other… and you can tell! They had to come up with wacky storylines to keep them apart. -u/Sherlockssocks

Weeds. A hilarious and intriguing show that slowly grew to be about a bunch of unlikable a**holes making bad, selfish decisions. When there's no one with any redeeming characteristics, there's no one for the audience to get behind. -u/rushandblue

Once Upon a Time. The first 3 seasons were good! And then after that they just kept getting worse. -u/bog--wizard

Not the worst offender, but That 70's Show tanked pretty hard once Eric left. He was sorely needed to make the chemistry of the group work. -u/Cleverbird

Suits. Loved the premise and first couple of seasons, but later it turned into just stupid drama between the characters and less about actual law. -u/yuriydee

House of Cards. The first two seasons were amazing. After that it started to get progressively worse. IMO, it should have been 2 seasons of him reaching the presidency, and then 2 seasons of everything going downhill. 4 seasons total, 1 for each suit of cards. 2 for building the house of cards, 2 for making it fall apart. -u/usernameunavaliable

Grey's Anatomy 100%. The show was great, but I just can't keep up with all the twists and turns and freaky accidents anymore. It's also a lot less funny. It should have ended seasons ago. -u/Classic-Breakfast-72

How to Get Away with Murder. The first season had some intrigue and plot...and then they just start murdering people left and right after that. -u/mbdallas95

Pretty Little Liars. I was addicted to this show but it could have ended in season 2. -u/CaoCaramelo

True Blood. When the fairies entered the picture, I exited. -u/toxic_pantaloons

The Flash on CW. -u/DiegoDynomite

Bones. At first it was a fresh setting for a procedural with likable, developed characters. But then Brennan got Flanderized hard starting around S4 and it was never the same. -u/monoDK13

Dexter was great but peaked at the end of season 4. Could not stand the last two seasons. -u/0rbitaI

Sliders. Went downhill after season 3, by season 5 it was ... meh. -u/NoAssemblyReqd

I actually think that Glee was like a fun guilty pleasure show when it first came out. Then after like 4-6 episodes there was a writers' strike and when it finally came back it just got worse and worse until it was unwatchable. -u/ClockNo4364

Catfish. Was a fun watch at the start, but it just devolved into fake, staged tripe. Not sure it was ever real tbf, but at least at the start it was somewhat believable. -u/HairoftheDog89

Falling Skies had cool things every season, but they were definitely running out of quality ideas or writers by Season 4. That finale was a joke also. -u/king0pa1n

Riverdale. I'm not convinced the guy who writes Riverdale has ever spoken to a real teenager. I stick this one out purely for the hilarity of it. Archie and the gang have super powers now and are fighting an evil wizard (I am not making that up). -u/VeryDPP

Designated Survivor. It started out very much like a modern day West Wing. But a key plot arc involved one of the key characters deliberately withholding his HIV status from his boyfriend. That's bad enough, but the show went on to vilify the boyfriend for being justifiably angry. Because f*ck consent, am I right? -u/CatOfTheDecade

Happy Days! Once Fonzie jumped the shark, while waterskiing and wearing his jacket, the show just got progressively worse. -u/Medicivich