Here are a couple of remixes by Wall of Sound, Inc.—the company, led by Jack Wall, who composed the soundtrack for Mass Effect 1/2. They recently gave an interview over at Over-Clocked Remix where they discuss the complexity of developing the soundtrack for Mass Effect 2, and they were kind enough to share a couple remixes of Mass Effect tracks.
EDITOR’S NOTE
I want to thank Jimmy Hinson—aka Big Giant Circles—for setting me straight on who produced these tracks. Nova Siberia being a remix that he worked on under Big Giant Circles prior to joining Wall of Sound, and Sound of the Galaxy was produced by Another Soundscape who also has a handful of killer video game related remixes.
Big Giant Circles: Nova Siberia OC ReMix
Another Soundscape: The Sound of the Galaxy OC ReMix
You can follow Sound of Wall, Inc. on Twitter @wallofsoundinc.
Not to be that guy, but if you Wall of Sound guys are interested in freshening up your website then drop me a line.
Haha, thanks for plugging this
One quick note though, the remixes are actually not by Wall of Sound. One is by “Another Soundscape” and the other is by myself prior to joining the group 
As for freshening up the WoS website, thanks for the offer, I’ll pass the word onto Jack!
Thanks for setting me straight Jimmy. These are both excellent tracks and I definitely want to give credit where credit is due.
No problem Matt, thanks again for plugging this for us! You rock!