It's been 20 years since Epic Games were founded and to celebrate this fact the developer has posted 20 music tracks from their games on their official blog, everything from Jill of the Jungle and Epic Pinball to Gears of War 3 and Bulletstorm is included. As a bonus you can also tune in to the Cole Train Rap from the first Gears of War.
All tracks are free to download, and if you just want to listen to them without downloading you can do so at Epic's Soundcloud.