An expansion pack is essential as more and more games are coming out where you need to use the expansion pack.  The expansion pack improves graphics on games like South Park and Star Wars and is essential to play games like Zelda Majoras Mask and Perfect Dark.  The graphics are greatly improved that if you put two monitors together with one having a nintendo with an expansion pack and one without an expansion pack you would be able to see the difference.  Dont miss out on some of the best games about at the moment, buy an exoansion pack and enjoy