With the constant barrage of Humble Bundle-like deals, I've developed a bad habit of buying discounted indie games and only playing them for an hour or two -- if at all. Although I feel guilty when that happens with pricey AAA releases, my conscience is usually clear when it comes to indie packs. Sure, they're absurdly cheap and the money generally goes toward a good cause anyway, but the real reason is because many of them have spectacular soundtracks that are worth several times the asking price of only a buck or two per game.
Indie games have been a great way for me to discover new music, particularly instrumentals, which is what I prefer listening to while working. It's hard to name one soundtrack as my favorite, but I've really enjoyed the music from Capsized, Sol Survivor, VVVVVV, Super Meat Boy, Superbrothers: Sword & Sworcery EP, The Binding of Isaac, FTL: Faster Than Light, Hotline Miami and many others, including big budget games such as the Splinter Cell, Hitman, Elder Scrolls and Mass Effect series. What are your favorite game soundtracks -- indie or otherwise?