What TV cancellation are you most upset by?

I'm still not over Firefly. Or the Orville.
- The Orville hasn't been canceled, yet. S04 will enter production this year.
  
  Thank you. It's been sitting lonely in my Jellyfin for a long time waiting to hear this.

Mind hunter, surprised i didn't see it mentioned
- Especially since it wasn't a real cancellation, just "on indefinite hiatus" followed by "never coming back" almost five years later. The second season ending very much set up at least another season.
  
  It was formally cancelled last year.
  https://popculture.com/streaming/news/mindhunter-david-fincher-reveals-why-netflix-series-canceled/
- Yeah, so good! This was Netflix’s True Detective and they just…dropped it?

Firefly
The answer is always firefly
- Too soon....
- I'd you love firefly check it dark matter. It unfortunately faced the same fate though.
  
  Yep, same characters too except they made the kaylee character into an adult pretending to be a child which was weird.
  Apparently there's a new dark matter on apple

Inside Job

freaks and geeks. unbelievably stacked cast but the network never gave it a dedicated time so no one knew when they could watch it. then it got cancelled before they aired half the episodes citing poor viewership

Firefly
- I wonder how the person who's decision it was to cancel firefly feels about this now. Do you think they were under a lot of pressures because of funding, or they just weren't that into the show, or was there a new show they wanted to divert funding to. Wonder what the story was there.

Pushing daisies was a hard pill to swallow. Such a great quirky show.
- And, from that same era, Dead Like Me.
  
  It sucks that it was only two seasons, but it did have a clean ending. No cliffhangers, or anything begging to be finished. I was happy with that.
  
  Both Brian Fuller shows

The Expanse.
Firefly.
- I don’t think The Expanse was really cancelled rather than it was ended at a story point that makes sense to continue from sometime in the future. There’s something like a decade long time skip and a huge thematic shift between books 6 and 7.
  
  That last season was disappointing to me

Sort of counts, but KOTH.
Fox took it off the air FOUR episodes from the finale to "make room for The Cleveland Show" of all things, the worst offering from those Family Guy clones imho.
Luckily, Adult Swim was kind enough not only to pick up KOTH, but to air those last missing episodes as well, and I have it all torrented by now of course and it was easy to find, but still, fuck Fox for that one (amongst other things, but I want to punch the specific exec that decided to do that right in the eye just one good time.)

Firefly

Better off ted.
Avenue 5.
Alien Nation.
My Name is Earl.

Amazon: The Rings of Power.
- I thought it still going. I think people were ok it being cancelled though.
  
  I thought it still going
  Exactly .... that's why I'm upset!

The OA

Darkwing Duck, it ends with the first episode of a two parter...
- Oof

Better off ted.
Show was brilliant
- I'd watch a spinoff of just those two scientists. They had such good chemistry together.

Santa Clarita Diet and Carnivale. HBO axed Carnivale, Deadwood and Rome back to back, and I still hold a grudge.
Edit: Enterprise and Lower Decks also still sting. Lower Decks is ao fucking brilliant and I hate that no one watches it!
- I LOVED Lower Decks. Enterprise was probably the weakest of the ST series.
  
  My love for T'pol politely disagrees.
- Enterprise was ruined by Les moonves, he specifically hates the show. It's still far better than the 3 nutrek series( I called them post jj Abrams.

Firefly
Raised by Wolves
Better Off Ted
- Raised by Wolves was very trippy but it felt like they knew where it was going and the acting was fantastic. At least it was as original as it gets.
  
  Why was it cancelled exactly?

Last Man on Earth

Utopia (UK)
The expense
- The expense
  A multi-season, high-tense drama series where Gary attempts to expense his lunch through SAP.
  
  I haven't watched the show, apparently they purposely end it because the new books is a time jump
- Utopia was really a good show

Teen Titans ended with a cliffhanger and then Cartoon Network put out Teen Titans Go! just to add insult to injury. Certainly the pettiest thing I've been angry about for nearly 20 years.
- I thought the show ended with the movie and it wrapped things up?
  
  Trouble in Tokyo? I guess it wrapped things up in the sense of it finished its own story, but didn't really resolve or conclude anything that was left hanging in the show.
  To be fair to the creators, the comic version of TTG does fill in some blanks about Terra's cliffhanger in issue #51, which is basically super condensed version of what I would have expected to be included in the season that got pitched and turned down.

Tuca and Bertie. Netflix cancelled it, then HBO made another season. But just before releasing it HBO cancelled it for a tax break. It's heartbreaking to think of the writers and animators pouring their lives into it just for nobody to ever see it.
- I forgot which other network did the same thing, created a movie than cancelled for tax breaks, I think it was warner brothers?

Limitless. It was just starting to get to the good shit when they cancelled it!
I was also upset by Star Gate Universe's cancellation. I hadn't been a fan of StarGate prior to its release. Seen a couple bits here and there but never just watched the show. After going through SG-1 and Atlantis, I can see why OG fans didn't like Universe. But I still think it was great on its own, as someone who knew nothing about the OG series when I saw it. But, if they do re-explore the same story and ideas, I'd want it to be the same campy shit that SG-1 was, instead of the serious tones Universe had.
- Any day now we are getting the next Stargate. Any day now!
  ~ fans ten years ago

In order that I remember them now
Drive
John Doe
The OA
Sense8
Limitless
Dollhouse
Tru Calling
Dark Matter
My So-Called Life
Witchblade
Carnivàle
Probably more, I'll add them as I think of them
Firefly would make the list, if I watched it while it aired. But I didn't see it till later.
- I cancelled Netflix because they cancelled Sense8 and The OA.
- Sense8 being cancelled was a crime
- My so called life was amazing.

Travelers
Or
Stargate Atlantis
- Stargate Atlantis was cancelled, but at least they made it home. Those Stargate Universe people are in for a lifetime of torture.
  
  The destiny crew have been frozen for 14 years lol already. At least ming NA made it into another show, at least for a while
- SGA was getting fucked by all the sg:1 writers that moved across and just kept writing sg1 with new names, it was a bit of a mercy kill
  
  Sga was cancelled for sgu unfortunately because MGM was losing slot of money, they needed a cheaper show

All time? Freaks and geeks. Was becoming the quintessential coming of age show, had hard lessons that were from the point of real kids growing up. Each character was relatable in their own way, and should have gone on for years.
Second to that is Arrested Development. And yeah it was rebooted but the cast had moved on. The show was on a great role and was just ahead of its time. The episodic nature of it just wasn't popular then.

I'll never forgive Amazon for cancelling The Tick.

Terminator: The Sarah Connor Chronicles. I would have loved to see how they planned to resolve that cliffhanger.

Ugly Americans.

Scavengers Reign and Raised by Wolves
- Scavengers Reign was fantastic and its cancellation was a travesty.
  Raised by Wolves was very good too but man... Scavengers Reign...

Kaos. That season 1 had me and my partner fucking hooked and they pulled the plug so fast it was hard to even finish it.
- Oh damn, really? I thought I read season 2 was a go but that was a cursory google months ago. Fuckin Netflix.
  
  I just double checked and yeah it's cancelled. Here's a quick article:
  https://www.thesun.co.uk/tv/30931197/netflix-drama-kaos-reportedly-axed-one-series/

Final space
- Im still debating on spending the $125 to get the book that finishes it.

Raised by wolves. Atheism vs Religion into the stars. It was so good and so much of the buildup was about to come to fruition. GAH!
- Needs a petition

Firefly and Pushing Daisies are staples in these conversations, so I'll throw in a less common one: NCIS LA.
I watched that show for over a decade. It was something predictable and comfortable. The show ending was like losing my favourite hoodie I've had for 14 years. Does it really impact my life? No. Do I miss it nonetheless? Yes.
- I stopped sometime during season 3 or 4, can’t remember. Without spoiling anything if I decide to pick it up again: do we know what G stands for? Don’t tell me, just nod or something.
  
  Yes, we do eventually find out what G stands for.

ReBoot. One of the most incredible, ground-breaking shows of its time, but it ends on a cliffhanger. I'm still holding out hope that we'll get a movie to tie up the loose ends someday.
- Alphanumeric!
- "I've always wanted to do that."
- I’m a little teapot…
  
  Prepare to taste the blade of my.... butterknife?!

Terriers.
Terrible name for a fun show.
- Yup, that is one of my favorite shows. So good. Donal logue and Michael raymond-james work so well together.

V (2009)
- Ah fuck, don't remind me. Just when it was getting tense.
  
  I stopped watching new / incomplete shows after that.

Lazor Wulf. Two seasons, with a forced change in animation studios between seasons, didn't give the show enough opportunity to grow.
Tuca & Bertie and Firefly as well. Maybe Lower Decks too

A lot of good answers already. I'll add Santa Clarita Diet. It's a nice little show.

Live action Tick.
- which one? The Fox or Amazon version?
  
  The Amazon one.

My Name Is Earl
- Came here to say exactly this. Ugh ...I hate that it ended on such a cliffhanger.
  
  They had no concrete plans for the specific cliffhanger at the end, but for the show as a whole we got some closure in Garcia's AMA at least. If you haven't seen it:
  I had always had an ending to Earl and I’m sorry I didn’t get the chance to see it happen. You’ve got a show about a guy with a list so not seeing him finish it is a bummer. But the truth is, he wasn’t ever going to finish the list. The basic idea of the ending was that while he was stuck on a really hard list item he was going to start to get frustrated that he was never going to finish it. Then he runs into someone who had a list of their own and Earl was on it. They needed to make up for something bad they had done to Earl. He asks them where they got the idea of making a list and they tell him that someone came to them with a list and that person got the idea from someone else. Earl eventually realizes that his list started a chain reaction of people with list and that he’s finally put more good into the world than bad. So at that point he was going to tear up his list and go live his life. Walk into the sunset a free man. With good karma.

Ash vs Evil Dead and Chucky
- Ash vs Evil Dead was incredible
- In the vein of Ash vs Evil Dead; I miss Stan Against Evil as well.
  
  I'm disappointed that Blood Drive also only got one season...

Patriot
- The best show that I still can’t convince anyone to watch. Excellent pick.
  
  Tbf it's a tough sell,
  "I've seen The Patriot before, I don't need to watch it again except maybe the 'Aim small, miss small' scene"
  "Oh it's a completely distinct entity with a close title? Oh ok, yeah sure I'll put it on the list."
  Never watches half of the list even stuff I really do want to watch
  
  ha, I forgot about this show - I remember it being well made

Terminator: The Sara Connor Chronicles
Really, Westworld, but no one had mentioned TSCC yet.

Since I haven't seen it mentioned yet and it deserves to be on these lists - Archive 81.
Such a great suspense show that was really starting to go somewhere by the end of the season.
- I also liked the show. However your comment about " [it] was really starting to go somewhere by the end of the season" is a good example of why it didn't get another season.
  
  Yeah, that sounds like I'm saying it found it's groove or something, I know.
  What I was actually trying to say is that it stood on it's own as a psychological suspense show, but then by the end of the season they inserted several twists and turns that made it something more. It would have been fun to see what they could do with a season 2.

Deadwood. It was my favorite show ever. They made a movie a couple years ago to wrap things up but it's not the same

Stargate universe
- Meh, the first season was horrible, Interstellar Gossip Girl. The second season was an infinite improvement, but it still felt like they didn't really have any kind of plan, just keep the plot moving along while abuse Battlestar Galactica camera work to ratchet up the tension.
  I get bleak, but this was bleak with no point, which is just sadness.
  
  Season 3 was going to rectify the lack of alien arcs. It got cancelled before that. And MGM had money problems too. According to the interviews it was going to reveal more about the planet builders back from season 1, and shed more light on the "resurrected people"
  
  I enjoyed the space adventure parts but every time they broke out the stones I lost interest.

Recently? The Peripheral, and Kaos.
- Kaos was so much fun, needed another 3-4 seasons.

Recently? Probably Kaos
- Kaos was great. I was surprised.
  
  Oh, I'd also like to add any projects with Neil Gaiman getting canceled, too. Good Omens, Sandman, and Deadboy Detectives.
  They were canceled for good reason, but still...
- I was heartbroken.

1899
Raised by Wolves
The Lazarus Project
and maybe The Expanse but as others pointed out due to the timeskip I expect them to continue it at some point.
- Raised by Wolves was so freaking cool
- I am so pissed about 1899.

Glow

If streaming shows are fair game, Final Space. So much passion poured into such an excellent production and Netflix axed it after 3 seasons.

Firefly
The Glades
Venture Brothers

I was quite upset by The Peripheral recently. And although it didn't release to much fanfare, Constellation.
- I loved The Peripheral
- I wasn't that upset by The Perpheral's cancelation. I loved the book, and the series pretty much just ignored it. I understand why, it would be very difficult to faithfully adapt the book, but what they came up with was much too modern-TV-melodrama for me.

Rome.

Pantheon
- If they had pulled off the ending I think it would have been my favorite show of all time.