What tv shows which you invested a decent amount of time into do you really regret watching and wish you used the time to do something else in your life (whether it be watching another tv show instead of extra squishy etc)

For me definitely Smallville (we were just crying out for anything superhero at the time), and Lost

I don't really regret any long-running show that I watched because apparently that defined "me" and my taste at the time. If its a show I stopped watching, its because the show changed (usually that's the case) or my tastes changed.

Sometimes I wonder why I still watch Hawaii 5-0

Never really have. However I can look back and think a show had a LOT of issues (Smallville for example)

Sons of Anarchy. Jesus Christ.

Smallville comes to mind, but there was simply no other superhero entertainment on TV when it aired.

I definitely regret staying with Supernatural after Kripke left as showrunner. They've killed off virtually every important character other than Sam and Dean, while bringing in a never-ending stream of disposable villains. I still occasionally watch but it's background viewing these days.

Probably Agents of SHIELD. I am grateful they finally destroyed Fitz and Simmons getting together around a month ago, that allowed me to walk away in peace.

I regret my three and a half seasons of Walking Dead...I was never more than meh on it..even the supposedly awesome first episode and grew to detest it with a passion...I would make an exception and go back to see Carl and Rick get eaten though...terrible terrible show (my opinion obviously)

The last season of Lost made me regret the whole thing somewhat but there was some really really good stuff in there as well that just had really bad payoffs.

All that really pops to mind.

Last season of Lost sucked balls but I don't regret watching the the rest of the series.

I watched my first episode of 2 Broke Girls the other day and immediately regretted it.

True Blood.

The series only got worse and worse (especially after the third season) and then ended on a note assuring that I'd have no desire ever to watch it again.

I don't regret watching Lost at all - great series, even if it didn't end on the strongest of seasons (not many shows do).

Definitely Lost. Such a waste of time.

Screw you, I loved every minute of Lost (except Jack's Thai tattoo episode).

I do regret sticking with ER and NYPD Blues long after the original casts left and the shows stopped being interesting.

Dexter

The tattoo episode is Emmy worthy compared to the final season.

ER was a long slow and painful decline.

NYPD:Blue had its UPS and downs and ended up going out on a very strong final season.

That show still bothers me when I think about it. Started so strong, had such memorable characters, so much potential and .. pure shit in terms of where they went with it. Writers obviously were pulling the story out of their asses as they went along. Thing that got me is that every season or so they'd sort of reboot what was important on the show: it's all about Dharma! Desmond and Penny! Time travel! Jacob and his brother! Meanwhile, none of that shit wound up mattering at all.

I have to go with Lost and Heroes. I'm not sure if Heroes qualifies as "long running" but it did seem too long for me. (And no, I didn't waste my time with this seasons revival)

How I Met Your Mother. All those years watching it, and now I can't even stand to watch it in repeats. The finale just killed all my interest in the show forever & ever amen.

I fear The Vampire Diaries is about to join this list, as I don't have the sense to stop watching it.

I liked most of Lost's final season and love the series overall, it just didn't go the direction anybody wanted. Of course, I also quit watching the show live during the last season and didn't actually finish it until years later which likely helped. After hearing how hated the finale was I sort of expected something ultra ambiguous, so the fact it was rather concrete just a bit goofy didn't bug me so much.

There were definitely a handful of duds that weighed down that final season, but still mostly enjoyable.

But overall, I don't think I regret watching any long running shows, as I get entertainment episode to episode or I just stop watching them.

Beyond Lost, which I do regret watching live given so much of the story ended up wasted:

CSI - Just terrible after Peterson left but like fools we stuck with it.
HIMYM - For some stupid reason we thought it might recover.
ER - There were good episodes here and there, but once the core was gone, it never was the same.
Ally McBeal - Another one that just dwindled into nothingness by the end.

Lost x 1000000000000000.

Scrubs - Seven seasons on NBC, most of which were incredible, then the "final" supposed one on ABC. But then ABC and Bill Lawrence didn't want to let the show go and went with a horribly retooled ninth season that couldn't move on from the previous eight. If they just focused on the med students and left the past in the past, it might have been a better contender for audiences and fans.

How I Met Your Mother - Like everyone said, that godawful finale. We only get glimpses of the mother that we were all teased with. Then it goes back to the BS that fans really hated. From what I heard, even the cast and most of the crew hated it. Of all the people Ted had to go back to... why not Victoria? Oh, because they wanted to burn that bridge by turning her character into something fans would hate.

I am completely convinced that the end game was absolutely them being in purgatory but when people figured it out after like 3 episodes, they changed course and just started making shit up on the fly. Dharma had a lot of potential, but they really screwed it up. Still probably the second best looking HD show ever, though Fargo is spectacular this year.

It does seem like Purgatory was the original solution to Lost but was nixed when it became the most popular guess in Internet circles. No should be scared away by the bitterness over Lost. The first five seasons are still my all-time favorite years of television. We'll never see anything like it ever again.

I couldn't think of anything then I saw a couple posts about HIMYM. Kept watching for no apparent reason other than momentum. Then when they started getting close to the end it got interesting again. Then the finale' just sucked balls. All that buildup just to kill her off right away. Now if the wife has it on it kind of annoys me. Ted, you loser she's a drunken slut that married your best friend, then you run over there like your wife meant nothing to you.

I think I've blacked out HIMYM from memory, totally forgot about it. What a chore to watch that show became towards the end. HIMYM and Lost are similar in that it was all buildup for a payoff that never came. I just don't get how those shows had so many years to figure out some - any - type of satisfying resolution and they completely shat the bed.

Actually, I thought "Smallville" got better and better as it went along (I still had problems with it, but it greatly improved when they started to embrace The Comics in an awkward hug, rather than shun them in embarrassment. That being said, I now use "Smallville" as a marker as to how far Comic Book "translations" have come on Television.