The biggest one for me is Mindhunter, a brilliantly atmospheric crime drama from David Fincher, I realise it's not exactly cancelled as such but it will be a big shame if a third series never happens.
The OA, brilliantly weird but Netflix being Netflix decided to drop it in favour of some other flavour of the month.
The Expanse, it's amazing that the home of the likes of Sharknado had such a gem and gave it up only for Amazon to take it over before promptly giving it the boot too.
An honourable mention to cross dimensional spy thriller Counterpart, dropped because it was too manly....
Any more?
Dungeons and Dragons.
Firefly.
In general most series should end before viewers tire of them, even some greats have gone on for far too long. Thankfully the wire only did 4 seasons and left us wanting more.
Firefly, obviously.
Jinx.
One that gets mentioned a lot, Firefly. Agree with Mindhunter too, it’s a great series.
I came here to say firefly.
Didn't expect to see it mentioned so soon.
Also Banshee
Boardwalk Empire for me if only for the fact they knew they'd been cancelled so tried, and failed to tie up loads of in depth threads in the finale season. I was always a slow burner so to rush the finish ruined the whole story IMO.
Firefly, obviously.
Lie to me with Tim Roth was another great one.
Loved "Finder" with Greg Stults, only lasted one season.
Let me be the first to mention Firefly.
Oh…
Loved “Finder” with Greg Stults, only lasted one season.
That's a good call, although I suspect we might be the only two people who watched it, so probably not surprising it was cancelled.
Lie to me with Tim Roth was another great one.
Loved that series.
Just watched the last one of Bull that I've always enjoyed.
Yes, Minister
police squad
Jericho .. I really liked that back in the day
The Wire was five seasons.
Gangland Undercover should never have been cancelled - based on true story and the main character goes on to infiltrate another bike gang.
Altered Carbon
Archive 81
Mongrels
Yes, Minister
Should someone mention “Yes, Prime Minister” at this point?
Firefly
Utopia (the brit version)
Rome
Deadwood
Space Above & Beyond
Jericho
And yeah

Why Don't You.
The Expanse final series was far too short.
Krypton Factor
Treasure Hunt

We as a family use to all love:
Primeval
Atlantis
Hardcastle and McCormack
The Big Breakfast
Treadstone...suspect it was bobbins but I ended up getting taken in by it. Not really sure where it would have gone though, 1 big surprise at the end really that hopefully would get answered.
I'm not an animal
Yes, Minister
I would love there to be more Yes (Prime) Minister in the world and I should really put it in the ‘tv you evangelise about’ thread, but I wouldn’t say it felt like it was cut short before it’s time. I’d rather it as it was than overstaying its welcome.
And firefly, obviously
Crossroads
The Expanse ran the full length of the novels in the first arc. All the books after that point are set almost 30 years in the future but with the seams people. It wouldn’t work.
Altered Carbon.
Firefly.
Almost Human.
Stargate Atlantis and Universe.
Ah, Space Above and Beyond. OORAH!
Kickstart.
At least Jericho was able to get a second season, only 7 episodes, to tie up some loose ends, and Firefly got a movie that gave some closure.
Containment - a pretty solid pre-covid quarantine drama - only got one and certainly if the producers know this at the time they acknowledged they would have ended it differently.
Similarly Dark Skies was a great ufo conspiracy series and only got one season, had a story arc for five, I think this and Jericho were probably before their time and would find a place on streaming platforms today.
The Tick, well I enjoyed it. We never quite found out what makes him.. Tick..
Going back a good few years, but does anyone remember flashforward? It was a good story and had the potential to develop into a great series but they scrapped it after 1 season.
Stargate Universe (the Robert Carlyle one).
Knowing me, knowing you
2 others i liked
brimstone (tv series with lori petty) and garth meringue's darkplace
edit just thought of millenium too (with lance henriksen)
Pushing Daisies
15to1 in its original half hour format.
Firefly
Pushing Daisies
Dead Like Me
The Sarah Connor Chronicles
Person Of Interest
Deadwood
Does anyone remember Outlaws, a series starring Phil Daniels as a jobbing legal aid lawyer? I remember really enjoying it for it’s dark humour and gritty style. It may not have aged well, but I was very surprised that it only got one season.
