The London Philharmonic Orchestra's The Greatest Video Game Music album is currently available on Amazon for $1.99. Regularly priced at $2.99, it loses $1 off the price if you use the code "GAMESMP3." The album features 21 notable tracks selected from the past three decades of video games.
The quality of the album is spot on. The "Tetris Theme (Korobeiniki)" should never sound that good ... actually, take that back, the theme to Angry Birds should never sound that good. There are also great arrangements from Metal Gear Solid: Sons of Liberty, Battlefield, Call of Duty and Final Fantasy. Be sure to give the album samples a listen.