Well, Edmund McMillen’s The Binding of Isaac is now available on Steam, which is a pretty damned good thing in itself, but also available is the official soundtrack for the game. Composed by Danny Baranowsky of Canabalt and Super Meat Boy fame, the 28-track album is available for however much you want to pay, from $.99 to fifty gajillion dollars.
Danny B’s a cool guy and an awesome friend, and moreover, the music is composed fantastically and immensely effective in conveying the tone of The Binding of Isaac. You can purchase and download it here.
A little bird also told me there may be a contest in the works involving multiple copies of this particular OST as prizes, so keep on the lookout for that.