One thing I've learned from "The Simpsons" on DVD is how to appreciate the show the way the writers wanted it to be seen. So many episodes have been subtle satires that were misconstrued by the fans as laziness or just bad writing. When you realize that episodes like "Das Bus" and "All Singing, All Dancing" are meant to poke fun at themselves, they no longer seem as awful as they once were. Listening to the commentary on "The Principal and the Pauper", for instance, and hearing Ken Keeler explain what his message was, I no longer see it as an attempt to ruin Principal Skinner's character, but as an exploration of the relationship that the fans have with the characters. Really, the message of the episode isn't complete until you hear the backlash and see how unusual it really is that people got so worked up over the massive deconstruction of such an unexplored character that they didn't really care much about before.
Furthermore, "All Singing, All Dancing" doesn't seem like a cheap clip show that the writers reveled in shoving in our faces, because it's now been revealed that the writers despise having to do clip shows, and they stuck it to FOX for ordering them in the first place by making them intentionally crummy. The end of "Das Bus" doesn't bug me because it's a parody of cop-out plot solutions that don't solve anything. Lisa's ultra-anal personalization in "Lisa the Skeptic" doesn't bug me anymore because the writers (and Yeardley Smith) have pointed out that, through the subtleties of Lisa's scene in the kitchen with Marge, she's not a heartless instigator - she just gets carried away. And most importantly, the overall "flexible reality" of the show has greatly changed my outlook on the show as a whole. The people who chastise the show for being too cartoony and who point out every minute error, even when those errors are intentional to service a joke, are the people who are so intent on finding fault that they no longer put the humor first. If it makes me laugh, that's all I need, and now that I've seen Season 9 on DVD, it makes me laugh just as much as the previous eight seasons. People often point to Season 9 as the first awful year of the show, but when you look at it through the writers' eyes, you begin to see what they were going for, and then the humor shines through.
Of course, this isn't to say that the season is perfect. There are moments that just don't hit the mark. "Miracle on Evergreen Terrace" is still my least favorite of the season because of its heartless ending. And Lisa is remarkably poorly characterized in "Bart Carny". But still, viewing the Season 9 DVD has drastically improved my opinion of the show post-Season 8. It'll be interesting to see if my opinion of Season 10 changes once they release that set - I won't be surprised if it does.
By the way, does anyone know how to access the easter egg on "Lisa the Simpson" that Matt Groening mentions in his introduction?