The Halo Killer.

The sequel to the original justifies it's hype. When playing the single player campaign, you will notice: Gorgeous graphics, amazing story, unfogettable moments, and alot of variety. Unfortunaltely the single player also has: graphical pop ups, 5-8 hours only of gameplay, and an annoying cliffhangar.
For the mutiplayer. Must I say? it's one of the best and the only problem is the cheaters online. If you havent played this you're missing out on one of the greatest xbox games of all time. But really, if you own an xbox is there any other game that delivers something like this? Get it and love it until Halo 3 comes out.