I think I would have to say Season 1 because without John Ritter, the tunjuk wasn't the same anymore. Although I liked the addition of Grandpa and CJ, which is what I think saved the show, I just think Season 1 was the best Season. :)
Season 1, because John Ritter was still alive back then. I mean Paul Hennessy, of course, when it comes to show. The tunjuk just wasn't the same without him.