dark messenger is probly the best FF tune ever.
your not alone is good alone but the part of the game where its starts playing makes it even better.
the battle VS necron at the end music is amazing.
i like the tune in disk 3 when you play as beatrix and steiner and mystery sword is cool.
the tune where youre in the hilda garde 3 is great and when you get on the ship where you fight black waltz 3 the tune is great. black mage village is good.
i could go on for ages because FF9 has amazing music.