@the footnote - But like you said, Haruhi was all those things at the same time, which is a feat in itself. Add to that the postmodern twist of having an arrogant whimsical girl being God in a sci-fi setting, and you have something that I (and maybe others who aren't just blind fanboys) care about.
Saying that you don't need to watch Haruhi just because there have been others that surpassed it after it aired (in singular aspects, no less) is like saying you don't need to watch NGE just because series like Rahxephon etc. are around. Also, I don't agree to some of your comparisons.(1)
I do agree about the problems the extreme delay of this airing has caused. They should have aired this as soon as they possibly could to maximize the fan obsession.
PS. I also read the novels, but the anime is definitely much better judging from the first season. Its all about the delivery, and this is a rare case where the anime version exceeds its source material. Heck, the God Knows live practically revolutionized music in anime.
(1) Higurashi is an awesome mystery series, but its comedy is nowhere near as intelligent as Haruhi's.
Kannagi was a great show (although somewhat a copy of Haruhi's setting), but Nagi is not an actual God (and all the powers that come with it), and that is what made Haruhi's whims integral to the plot in the first place.
Bamboo blade was quite interesting, but it lacked originality. I would hardly compare it to Haruhi, much less say it exceeded it.
Shigofumi had the originality, but lacked the solid comedy and character development Bamboo Blade had. I didn't wait for each episode and watch it asap for these two shows.
Ef was not better animated. It was just slightly better directed, but that is mainly due to the artistic style it chose. You're right about Kanon and Clannad though.
But, this is also just my opinion.
EDIT: removed Aria comment upon reflection.