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

Otherworld

Johnathan Banks would have had a billion Emmys by now if they had just followed the 45 season and 6 movie plan.

Revolution.

Cool ideas/setting, and Giancarlo Esposito was involved. Low-key haven't moved on yet. I get it, maybe the writing could have been better, good ideas, but not so good execution.

A lot of them have been listed already, so I’ll throw in “The Riches”. Cancelled during the writers strike in Hollywood.

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

Without a doubt, Netflix's The Society. Made all the worse for the fact that it was renewed for a second season, and was less than a week away from starting shooting that season when COVID lockdowns began. Rather than postpone like so many other movies and shows did, Netflix decided to cancel it entirely.

The Society had so much potential as a really engaging mystery as well as some serious sociological storytelling. It's so disappointing.

Captain Star

Arliss

Outer Range

MANTIS

Threshold really should have gotten more than one season. Unfortunately, I don't think anybody's ever heard of it.

The Pretender. Mostly because they had just had a huge cliff hanger. And the made for TV movies never got aired in my country.