The huge 120GB detachable hard drive is the largest available on any console. It lets you save your games and store television shows, movies, music, pictures, trailers, extra game levels, demos, and other content available from Xbox LIVE Marketplace.
The Xbox 360 120GB Hard Drive is the best option for media enthusiasts who game on Xbox 360. It is the largest storage option for Xbox 360. Expand your Xbox 360 experience with downloadable content. Save your game progress, Xbox LIVE gamer profile, game demos, and custom soundtracks from your own music collection. Download movies and television shows from Xbox LIVE Marketplace. Play original and retro games in Xbox LIVE Arcade.
The Xbox 360 120GB Hard Drive includes a data transfer kit to easily migrate all of your saved data from your 20GB HDD to your 120GB HDD. It comes preloaded with great HD game demos, videos, and an assortment of Xbox LIVE Arcade game trials.

* Fusion color
The 120 GB Hard Drive matches the style of the original Xbox 360 console and 20GB Hard Drive (the black 120GB Hard Drive is only available as part of the Xbox 360 Elite console package).
* Game saves
Even the most dedicated of gamers could spend a lifetime trying to fill up 120GB with game saves.
* Music
Rip CDs to the hard drive with reckless abandon and no concern for space constraints.
* Videos
Xbox LIVE Marketplace offers a wide variety of video content from gaming and movie trailers to television programs and HD movie rentals.
* Pictures
Download gamer pics and dashboard themes from Xbox LIVE Marketplace or create your own with the Xbox LIVE Vision Camera. Keep a huge assortment on hand to suit any mood and whim.
* Gaming demos
As gaming demos become deeper and more detailed with stunning HD graphics, they also take up a lot more space -- no longer a problem with the 120GB HDD.
* Xbox LIVE Arcade games
New games are being released weekly. Have no fear of owning them all with the massive storage option of the 120GB HDD.