For me if I had to pick a good contender it would be the UK version of The Office.
I know many tend to debate how Ricky Gervais really fell off and how he repugnantly acts like a whiny centrist edgelord but me personally IMO I actually don’t think he was ever funny not even a little.
His big break through television was just so painful to sit through it’s so charismatically boring the characters are completely generic at best (notably Tim) or straight up insufferably unlikable at worst (especially the protagonist David FUCKING Brent) and most importantly the humour is just embarrassing.
Always seemed like The Thick Of It but without the nuisance tongue in cheek and charming satire.
So.
Star Trek was genuinely groundbreaking when it aired. First was that basically no other sci-fi story had a hopeful vision of the future, so it was instantly different. Star trek was a meritocracy, it was post-scarcity, characters where hailed for being competent moral people, instead of morally bankrupt nepo-babies.
Second was that the show treated people like adults, a lot of the storytelling involved significant moral conundrums, and included scenarios with no easy answer.
Finally, the shows sci-fi setting let it tackle ideas that otherwise would be untouchable. Racism was shown to be absurd not by having black people and white people, but you could see a whole planet where people half-white and half-black would oppress (and be horribly racist) towards exactly the same people, but who had the white part on the other side of the body.
Finally, the casting for the show, and the characterization was amazing. Kirk is (imo) a boring character, but the dynamic of Kirk Spock and Scotty made for genuinely interesting interpersonal dialog.
Granted, its been done again and again, and done better (Notably, TNG is better in almost every way IMO), and so the formula got stale, and you cant help but compare Star Trek to the copies, several of whom inevitably did certain parts better.