As far as I remember Xbox 360 games do not need to be installed to the Hard Drive like PS3 games need to be. Does this mean it is possible to play any Xbox 360 games without a hard drive connected to the system?
Yea you can play them, but some games have fairly big game saves. On top of this there are often patches released to fix bugs and stuff. Without some sort of storage on your console, you wont be able to properly play the game. The hard drives are pretty cheap at this stage so it is best you use one.