The music for "The Grandmaster" is outstanding and it fulfills both aspects necessary for a great soundtrack: (1) the music conveys the themes/tone in the context of the movie; and (2) the music is also pleasant and rewarding to listen to on its own. This is one of my favorite soundtracks of 2013.
The movie has a lot of new music, but it also re-purposes older tracks from other sources (including some memorable work from Ennio Morricone). It's hard for me to pick favorites, because I enjoy each and every track... but below I've listed the ones that I'm replaying most often on my iPod.
 Main Theme I - Opening
 Love Theme II
 The Gold Pavilion
 Main Theme IV - The Sacrifice