Shows that fell off but are still worth watching the early seasons?

Basically I’m looking for the “good seasons” of shows that otherwise aren’t worth watching. I’ve seen my fair share of shows that started off super amazing, then got pretty boring later on (Haruhi Suzumiya, 86, the original Naruto).

Basically just give me the “watch this season” of a show that otherwise isn’t considered very good besides that one part