I think that the LOTR movies are very good, but AUJ is little short of a masterpiece. There's a lot of stuff that PJ did with LOTR that I don't agree with (the lack of scouring of the Shrine being the most important), but almost everything he did with AUJ improved it - the only thing that comes to mind that he shouldn't have done IMO was meddling with the timeline so that Gandalf organizes the journey and then learns about the Necromancer while he is on that journey. What on earth was Gandalf's motivation for going there in the first place then? But on the other hand, it's also understandable that PJ didn't want to have a third interlude before the story begins.
Also, I'm definitely in the "the extended edition of AUJ was too short" camp.
I'm going to disagree with most of this. First, my LOTR background:
I read the Hobbit too long ago to remember; then after I saw the first LOTR movie in theaters, I read all 3 books before the second came out.
Anyway, first off I thought the LOTR movies were all really great, while the Hobbit was just ok. Hard to say exactly why, I just know that I didn't leave the Hobbit with the same feeling of "wow that was awesome, can't wait til the next one comes out; can't wait to go see this one again" that I had after each LOTR. I'll still see the next Hobbit in theaters though.
As for the lack of the Scouring of the Shire... I wasn't at all surprised or disappointed by it. When I was readying Return of the King, I got to the part where the ring was destroyed, and was pretty much like "wait, what? There's still almost half a book left." Then I finished reading it, and pretty much just thought it was really anti-climactic. I didn't like at all how it was done. And I remember thinking very specifically "there's no way that this whole part is going to be in the movie when that comes out. It just doesn't make for a good movie to have all these events AFTER the main climax of the film."