UK sitcoms – many great sitcoms lasted exactly 2 seasons
of the shows lasting just one season, my favourite was “If you see God, Tell him” a black comedy about a man (played by Richard Briers) who after a head injury has a very short span of attention and becomes obsessed with adverts – believing them, imitating them.
However, I have doubts if it was actually cancelled and believe it was always intended to end after 4 episodes.
Similarly I can’t imagine “Whoops, Apocalypse” ever being considered for a second season after the finality of the last episode.

Then there is “tlc” a hospital sitcom (more black comedy…) – the highlight of which was, in my opinion, Tim Brooke-Taylor as the hospital chaplain – a former surgeon who after a nervous breakdown still tries to work in the hospital anyway he can (despite his lack of interest in religion)

runners-up – “KInvig” – about an electrical repair man who fantasizes that a new customer is from another planet and in love with him (and only pretends to hate him) – the series was written by Nigel Kneale – better known for serious science fiction/horror series.
“I, Lovett” about an eccentric inventor who talks to his dog, etc
“Dead Earnest” about a man erroneously sent to Heaven trying to cope with life there or finding a way back to mortality.

I thought it had lots of laugh out loud funny moments every week.

Rob Lowe, was the lead. His part was as a pompous actor, that had played a lawyer on TV, but decided to start going to actual court to litigate cases.

The bit was that judges were so happy to have a famous actor in their court that they would wave the fact that he hadn’t passed the state bar exam or understood the legal system.

I actually can’t pick a single favorite one-and-done sitcom:
Disqualified if you count the movies: “Police Squad!”
Animated: “The Oblongs”
Guilty pleasure: “Hot Properties,” an ABC hybrid of “Designing Women” and “The Bob Newhart Show,” with Gail O’Grady, Sofia Vergara, Nicole Sullivan and Christina Moore as the four real-estate women, and Evan Handler as the dentist who’s also on their floor in the urban high-rise. It was much worse than I’m making it sound!
Honorable mention: “The Robert Guillaume Show,” which I use to remind myself that “show with a black man dating a white woman” was too much for a lot of people even in the 1980s.

That last show ALSO has one of my favorite sitcom gags ever: The pilot has Guillaume’s Edward searching for a secretary, and the montage of applicants includes a disheveled man who’s typing at the typewriter at absolute lightning speed. Edward, impressed: “You know what? When you first came in here, I was judging you by your appearance, but now I see what you can do, and I feel like” (finally sees the paper from the typewriter) “THIS IS GIBBERISH”

https://en.wikipedia.org/wiki/The_Second_Half

And, no doubt, Paul Lynde’s sitcom will be on many peoples list:

https://en.wikipedia.org/wiki/The_Paul_Lynde_Show

My list for when you inevitably ask “What Is Your Favorite Drama That Was Canceled After Just One Season?” will be much longer! 😉