I just finished watching the fourth season of Curb Your Enthusiasm, and that has to get my vote. There's just no other show that makes me laugh that much with every episode - not even Arrested Development. The scripts and ideas just strike me as being completely original with each show. Aside from the fact that I can't stand Richard Lewis, I can't think of an episode from any of the four seasons I've seen that seemed weak.

Maybe the Simpsons wouldn't be so hard to write for (hypothetically) if they let the characters grow and change. No one ever gets older or wiser. No one evolves on that show. It's been on for 17 years? How about a little forward momentum?

from what i have read, Larry David and writers come up with a basic idea, and everything else is improvised.

I would have to say the new show on HBO Rome I have watched each episode twice and I am still completely lost and dont know who is who yet. Also I didnt know they used the word ***** back in the day like that