Colossally Epic
It really is an amazing piece! It kicks in right at the beginning and then just takes off. I love the part at 0:42 with the bell sounds, it's really neat. Also love the part with strings just after it at about 1:09. The whole song is masterfully layered and while it sounds incredibly complex, nothing seems to be trampling others or sinking in the background.
Granted, I'm kinda a sucker for this kind of music, but I really feel this deserves a weekly top five. The '5' button on the rating bar might get broken on this song with all the clicking I'm doing to it, haha.