I'd like a more active TV circle, lol, so I hope this gets a discussion going.
Mine is probably Arrested Development. I love how many jokes pay off on rewatch. So many of the jokes that come in the later seasons are made better by being able to rewatch the earlier seasons and see how carefully the show runners laid out the groundwork for the punchline. It's also a show that does well on a rewatch because they had such a good grasp on the characters and the tone of the show from the beginning that there's no "settling in" period where they have to establish everything for the viewers. The first season is often the weakest for a lot of shows because so much time is spent establishing the environment and the "vibe" that it's not worth a rewatch, but not Arrested Development. They hit the ground running and never stopped.
I know people are torn on the fourth the and fifth seasons, but I actually really liked the fifth season. It leaned into the sourness and negativity that always underlined the show in a way I think really worked.