Undoubtably, the most aniticipated game for the 360 this year was Gears of War, a tactical shooter made by Epic Games.
http://gearsofwar.com/Emergenceday/ <--- Official website
I, of course, couldn't wait for it's release, and already own it.
There are some very interesting aspects to the game. For one, the camera angles are very cinimatic, often times feeling like it's being actually carried by someone behind you. The active reload is also a cool feature; while reloating, a meter apears below your weapon ammo gauge. A bar moves from the right of the meter to the left. If you leave it alone, the bar reaches the end after a few seconds, and your finished reloading, but if you hit the reload button again at the right time, you reload faster and recieve a damage boost. Naturally, if you mess up, your weapn jams, and you have to try again. This can be critical in intense firefights.
The deathmatch play is excellent, require actual tactics and teamwork to win.
Also, one of your guns has a freakin' chainsaw bayonet. What's not to like about that?
http://www.gamespot.com/search.html?qs=gears%20of%20war&sub=m&stype=11&type=11 <---- Trailers & gameplay movies (much gore)
http://www.gamespot.com/xbox360/action/gearsofwar/review.html?sid=6161188&tag=topslot;action;3 <--- Gamespot review.