GameFly cut prices on select used PlayStation 3 and Xbox 360 games to under $20 each. (Browse the respective sections to see all available titles.) With titles starting at $9.99 with free shipping, several items are at or near all-time lows.
A best bet is the used SSX for PlayStation 3 (pictured) or Xbox 360 for $14.99 with free shipping. That's $15 under our April mention of new games and at least $22 less than the lowest total price we could find for these games new.