I think that John williams was at his best with ESB. Great score, and in my opinion, the best he's ever done. (Though I loved the score to the first Harry Potter film) I also agree that the level of music indicates how good a Star Wars movie is. ESB had the best music, and was the best Star Wars film.

But Williams isn't my favorite composer. He reuses the same tunes too much. Using tunes many times isn't bad, but Williams can't always pull it off. My favorite composer of today would have to be Howard Shore. No score will ever outmatch that of the LOTR trilogy.

Anyway, Williams was at his best with the OT. Sadly, the next version of Star Wars will probably have the whole score replaced with a Gungan chorus.