If you own a 360, you need this game.
When I first saw Gears of war I was blown away. By its graphics, gameplay, music, just about everything. I knew that this game would become the next "Halo" for the Xbox. The point is. is that you need Gears of War in your 360 collection no matter what. I've rarely been this impressed by a video game.
Gears of War--the single player campaign, at least--is a truly stunning and epic experience. The game is rated Mature 17+, so it's obviously not for kids, and the violence, language, and horror elements are indeed for mature audiences only. But the overall presentation in Gears of War is unsurpassed. It is a gorgeous, fun, and highly playable game, and one I'm eager to play again and again, especially in co-op mode.
My complaints are few and all minor. The unique cover combat mode is fine, though the game overloads the controller's "A" button to a dangerous degree. The single player campaign is arguably a bit short, though the overall story is far more complete than, say, that of Halo 2. And there are minor bugs, though nothing as glaring as those in Call of Duty 3. Multiplayer appears to be a bit limited, though Epic could easily fix that with online updates.
None of this really matters. You need Gears of War. You want Gears of War. Highly recommended, Gears of War is the game of the year for 2006.