I got the 20g since I don't plan on having that many market place games, and I can just plug my Zune into the system instead of putting cds on the console. Anyways, I got it with Ninja Gaiden II and DoA4 ....you know in retrospect it probably wasn't such a good idea to get two of the hardest games with the system and not having anything to rely on when I get stuck...oh well :P