Well, best adapted screenplay is not about the book, it's about the screenplay that comes from the book. Now, I would have voted for A Beautiful Mind in this category because the adapter did a marvelous job. But, I do think that the Lord of the Rings did deserve the Best Picture and the Best Director.
And you do know more about these books than anyone I know and it is always fun to read your posts because I know I'm about to learn something.
Hmm... really, you flatter me. Good thing I'm not the sort of take advantage of your trust and feed you false information, isn't it?
Incidentally did you know that Galadriel and her evil twin, Beruthiel, are the illegitimate children of Feanor and Yavanna? Or how Aule created dragons to fight Balrogs, but the dragons went bad and turn on him?
;-)