If your after the must have 2008 Xbox 360 game, Gears Of War 2 is it - if your after either version(standard or limited ed) it's gonna be expensive.
"Epic saga: Gears of War 2 continues the story of Marcus Fenix and Delta Squad, locked in an increasingly desperate battle against the nightmarish Locust Horde for the survival of humanity. Gears of War 2 is an epic saga of survival, loss, and retribution.
Technological advances: Gears of War set the standard for high-definition visuals and became the game to which all others are compared. Gears of War 2 raises the bar even further with the amazing technological advances of Unreal Engine 3."