I was super happy when they added both of the Castrum Novum tracks. I've been waiting for those to be in game since launch.
Beneath Bloodied Banners is also one of my favorites. The first time I saw the Prerelease Trailer, and this this track kicked in (at 2:34), I knew Uematsu was back. His return to Final Fantasy, more than anything, made me want to play this game.
The post-Uematsu music for XIV is all really good, too (especially Garuda and the final AF quest music), but I miss Uematsu's presence. I wish he would write some more music for us.