This article proposes 1997 (Season 9):
Rise and fall of a comic genius
I can see arguments for earlier or later.
I say Season 7 is best, but some later episodes are great too.
Thoughts?

i've long contended that the best seasons were 5-8, though there are notable exceptions to that broad stoke.  The article brings to mind Homer on an electric pole repeatedly clipping the same cables and getting electrocuted or an eerily similar scene in the kitchen years later.

They need to give it up before "the show eventually becomes unprofitable."

that it would keep going until the show was no longer profitable?
Couldn't find a proper quote: only an episode capsule:
http://www.snpp.com/episodes/4F20

and a script in french:
http://www.simpsonspark.com/scripts/s8/4f20.php

[Maybe if you click on "English Page" on the left it would take you to an english version of the page - I for one was too skeered of French cultural imperialism to do such a thing ...]

Well, I went and saw it and it was not a flaming piece of crap as I expected...
In fact, I rather enjoyed it.
I laughed a bit but not nearly as much as the ~10 year old who was sitting across the aisle from me. He thought the movie was freakin' hilarious.
Anybody else see it?

maybe I'll go htis weekend.

We will probably go see it soon... we have this nasty little habit of waiting til movies come out on dvd and buying them, since it's cheaper than enduring 2 hours in the theater.