If you have a hard drive for your XBox 360, there are some games that can be moved off memory cards - and others that cannot. Be sure you're prepared!
Here are the list of games we have tested, and the status of each one. The test we were doing was to load in a memory card and to try to transfer the save game to the hard drive. The point here is if you buy a core system and then are able to get a hard drive later on, which games can you then move to your hard drive?
Call of Duty 2 - fine
Condemned - fine
Kameo - fine
King Kong - fine
Need for Speed Most Wanted - fine
Perfect Dark - NO CANNOT MOVE
Project Gotham Racing 3 - fine
Quake 4 - fine
Ridge Racer 6 - fine
We actually have hundreds of games here but haven't sat down and tested each one. We only tend to test files when someone writes us to ask if it's possible. If there's a game you're interested in us testing, let us know and we'll give it a try! We'll also update this list so that the information helps other people out there searching for information.