All the tracks in MDK2 is just pure awesome!
I also like some of the tracks in Commandos 2.
And the tracks in Advent Rising is epic. If you like the live orchestra and choir.
And a lot of the music from the Monkey Island games, but that is a given.
The Time has Come - from Devil May Cry 4 that appears when ever Nero fights is also really cool, not the "We Will Never Surrender". Once you get to the slow end part, it just looses it's awesomeness.