As a fan of Jesper Kyd's work, I could mention these two:
-music specifically composed for AC2 CGI trailer (also served as intro in the retail game), it is similar to certain tracks from AC2 OST (as expected) but this particular trailer track was never released:
http://www.youtube.com/watch?v=9FyFYQ4iBYg
-from Darksiders 2, this bloody awesome track (The Makers Guardian) wasn't included on the soundtrack, don't have the slightest idea why knowing they had tons of space on the CDs left:
https://soundcloud.com/jesperkyd/dar...akers-guardian