UPDATE (12/10/12): I just realized that I forgot about Mihály Vig's beautiful score for Bela Tarr's Werckmeister Harmonies. So, it's replaced Ennio Morricone's win for Malena in 2000. Sorry, but I HAD to fix that.
Best Original Score:
2000: Werckmeister Harmonies (Mihály Vig)
Oscar winner: Crouching Tiger, Hidden Dragon (Tan Dun)
Was this nominated?: No