Season 9 was in my opinion, very good. Kramer's plot was very funny. His problem with the kids from the building and having all that anger inside led him to destroy something very valuable. I couldn't stop laughing with this Endora's comment and then when he told George that he 'owed him one'.
I like how that plot fits with George, whose dysfunctional family has one the best dynamics of the season. And George was very stupid to follow that well, stupid idea.
Elaine has some trouble of her own with Mr. Lippman's son and well, at some point I wished I could've seen her and Jerry together. Well, it was good while it lasted.