Grand Theft Auto IV is now downloadable from the Games on Demand service for Xbox 360.
It costs only $29.99 and 7GB of free space to purchase and experience this beast of a game without even leaving your sofa! The price is roughly the same as retailers charge for the Platinum version of the game, and just $5 more than what GameStop charge for a preowned copy.
If you value your time, this is perhaps the best way to get the game!