So after watching Kakipi1000's 3 hour Unleashed run...

It was brought to my attention again (for the third time now) how simply amazing the soundtrack is to listen to.  For me, it's one of those soundtracks that works very good in game, but somehow sounds MUCH better on it's own outside of the scenery it attaches itself to.  The most remarkable tracks for me tend to be the night time stage/hub tracks.  I'm not sure exactly who was in charge of this group of music, but I can at least give credit to the person who was in charge of the OST, which is Kenichi Tokoi - a man who has done some amazing work with Sonic games dating all the way back to Sonic Adventure 2, I believe.  His most popular track is possibly Planet Wisp Act 1 from Sonic Colors.

This is without a doubt, my favorite track in the game.  It's incredibly beautiful.  I could listen to it all day.