I still fall asleep watching TPM. Its just boring for the most part. Does the plot advance the storyline and answer questions? Absolutely, but its got as many detractors as positives. I like pretty much everything Jesse mentioned, in addition to the "origins" of R2 and C3PO. There are some great pieces there, but I didn't like Jar Jar, trade embargos, midichlorians, Jar Jar, the goofy Anakin saves the day ending, Jar Jar, aliens all talking basic, or Jar Jar. They could have told a much more interesting story with about the same plot minus trade route crap and Jar Jar.
I'm also in the camp of being okay with delayed criticism. I did like the movie more when it first came out just because it was something Star Wars after so many years. They could have made a story about the latrines in a Star Destroyer and I think I would have bought into it back then. But its certainly okay to look back over time now that the PT is complete and have a change of heart.