(well besides that they finished because hur dur that would be obvious)
basically, any tv shows which irritated you beyond belief and you were like mmm no more of this nonsense, bye? or any other reason?
also if any spoilers, please put in spoiler tags thank you!
I stopped watching bones and new girl after they irritated me :x which is a bummer because they were both my faves when they were on in their respective earlier seasons :C
also, I will never touch himym after hearing about the ending
I stopped watching Once Upon A Time a short while ago. When plots get so overly complicated and/or large I lose interest fairly quickly. There are a couple that I was going to stop watching but it ended up they were going to be done within that season so I just finished it up. I'm thinking about stopping Brooklyn Nine-Nine, Doctor Who, and It's Always Sunny in Philadelphia, too, because although I love them, they've gotten a bit repetitive and I don't necessarily have the time anyway with school and work. I keep up with all of 4 shows now D: Bob's Burgers, The Librarians, Teen Wolf (because it's only got a few episodes left), and Sherlock (because it's hardly ever on anyway) ^^;
I stopped watching Supernatural a few years ago now. That show has 100% run its course, and has been dead to me for a long, long time. lol I wish they'd just stop, but they somehow keep coming up with more and more convoluted ideas to keep the show running. ;^; It used to be so good, too! That's the sad part. I used to really love the show, and I feel like they're just gonna keep driving more people away if they keep it going. lol
sleepy hollow bc the only good thing after season 2 was ichabod's hair tbh also just kind of stopped watching supernatural at some point. i mean, i loved it, but they're just beating a dead horse at this point and it's pretty clear they've run out of ideas.
if you haven't watched it yet the new season of sunny is SOLID
oh my goodness! I forgot about sleepy hollow, yeah it was pretty good to begin with but I couldn't stick with it after that last season. I have managed to keep up with sunny so far and oh wow, that cricket episode had me in stitches
... Soo many - oh boy. WILL CONTAIN SPOILERS!!! cannot stress enough.
I recently dropped Teen Wolf. I have loathed it ever since Derek departed (and even before, it was getting on my nerve). I cannot handle queerbaiting and the producer/creator is a pro at that. I dropped The 100 when Lexa and Lincoln were killed. That was the last nail in the coffin to me. My brother kept up a bit with it but he told me it was a trainwreck. Good riddance. I stopped Reign ... for absolutely no reason. I think it was getting repetitive and boring. They have beautiful costumes tho, ha ha. I pretty much dropped everything: How to get away with murder, Legends of Tomorrow, Arrow, Supergirl ... More recently, I dropped The Magicians.
I'm so damn difficult :c
oh yes I forgot about arrow lol that trainwreck of a mess xD let's see, I dropped grey's anatomy a looong time ago there must a bucket load of shows I'm forgetting :"D
I feel you on The 100. I dropped it for the same reasons.
I dropped The Fosters, too, and I'm moving towards dropping Supergirl. I haven't officially dropped Orphan Black but I didn't finish the last season. I should, but.. I don't really know why I'm starting to find it boring.
Same, it's such a drag nowadays. My brother still watches it an occasionally I'm in the room while he's watching it on the TV and I'm just like????? I didn't think a TV show about zombies (and I love the zombie genre) could be so boring.
I don't watch much TV to begin with, but one show I used to watch but just lost interest in is Survivor. You know, that reality TV show where they strand a bunch of people in god-knows-where and make them do challenges against each other. I loved it as a kid but now it just bores me? I don't even bother trying to keep up with it anymore, when there's a new season. As for others, I used to watch Doctor Who, but I'm reeeeally uncomfortable with change and so I stopped watching after Chris Eccelston left. It's not that David Tennent is a bad actor, I just really loved and got attached to Nine. :c I did give Ten a chance, but I just couldn't. I couldn't do it. I stopped watching Attack on Titan after episode 10 or so, mostly because my Netflix subscription ran out and I didn't have the money to renew it, but also because it got boring to me. I might try it again some day, though, but I doubt it. I honestly prefer horror or silly stuff to action. So honestly, I prefer the Abridged Series to the actual AoT. :P
I used to watch South Park and Family Guy, but just found them really stupid now.
Laugh and the world laughs with you...Fart and you stand alone.
Seconding Walking Dead.
Got way too boring and they killed off all the characters I liked. And then brought one of them back with a loljk! and then...killed him again.
And uh...I tried to watch Doctor Who, but I only made it through the season with Chris Eccleston. As soon as it switched to...Tennant(? I think), I lost interest.
Oh and Arrow. First couple of seasons were alright, but now it should just be called Felicity and Friends. Ugh. Same for Flash. Watched the first season and got irritated with the cross-overs and bailed.
I forgot I also dropped iZombie, Shameless (but I'll catch up and see if I still like it), The Flash, Falling Skies, V, The last ship, True Blood, The Vampire Diaries ... Ugh. I'm so irked by TV nowadays.
Lost, the original Heroes and Once Upon a Time. All because the fans were batcrap insane and made it intolerable.

breaking bad... we were binging it and just stopped after a while
Once Upon a Time: plots became poorly written, poor character chemistry imo
West World: My cousins Loved it and binge watched it all.I love the premise but didnt get that into it. I may finish later but Im in no rush.
Walking Dead: Got boring. My favs kept getting killed. Darrel's character arc got stale but he is so beloved by fans that nothing will happen.
Supernatural: Havent watched it since the Mark of Cain season. The show is fun but started feeling repetitive and the plots get more convoluted.
I stopped watching Doctor Who after the Eleventh Doctor left, New Girl, Once Upon A time, NCIS, Hawaii Five-0 and The Flash.
I loved each of my mentioned shows but they don't hold my attention anymore. Most of the time the plots go just on and on and on without going anywhere. (I don't have time for that haha).
(and the ending of Lost was so disappointing I wondered why I watched in the first place. It began so promising).
Dropped OUAT a while back. The plot became frustrating and when they ruined some of their previous character development I just gave up. I'm tempted to go back and see what I missed but I don't have the time. Dropped Grays Anatomy too. I was growing tired of all the insane issues and losing so many of the characters I was originally a huge fan of. I got behind a season and heard how it ended, just didn't have the desire to go back to it. New Girl was another one I really enjoyed, but it got drawn out and a little repetitive so I gave it up. Can't bring myself to give up on Supernatural but in my opinion it's gone downhill since Season 5. It has good and bad moments, but I'm still attached to the characters.
I used to really enjoy watching True Blood, I own/watched up until the third season, and after that I just never got back into it... I would like to maybe one day. Pretty Little Liars was another one I really enjoyed when it first came out and I tried to keep up watching when I was in college but ended up falling behind and never really got into it again.
I don't really enjoy watching big shows on TV though, and once a series gets too big I just tend to lose interest unless it's really something I like.