Hunter, while I might agree with you on certain choices expressed, I now beg you--I am BEGGING. Please give us an example of what you consider to be a beautiful score. You wasted two or three minutes of your life to read the thread and post a reply, so waste another 5 seconds to add that "Such and such is clearly the most beautiful score ever". You don't even need to back the statement up.
As for my personal opinion, since I bothered to reply at all, I think it's hard to single out the most beautiful score ever because so many scores split me down the middle (for example I think Carousel has some great songs, but then it has some less than beautiful songs).
As far as a total score goes, my vote definitely goes to Piazza. Its main concern is sounding pretty, and it does that magnificently. It hardly ever sounds like showtune music and sounds beautiful most of the time (sure, it has the atonal "Aiutame" but you'll live).
There are parts of Floyd Collins that are lacking, but the parts that excel more than make up for it. "How Glory Goes" is an utterly transcendent song. That song along makes Floyd Collins one of my favorites, but luckily it also has "The Riddle Song", "Daybreak", and others.
An unconventional choice: I think the music to Camelot is really gorgeous. Enumerate the show's flaws if you will, but the music is just beautiful.
Also: Showboat, Porgy and Bess, Sunday and Sweeney and Passion... lots!
yr ronin,
joey