Even if you don't have Xbox Live, it is well worth your every dime & brings together some of the best elements in games.
User Rating: 10 | Call of Duty 4: Modern Warfare X360
I can throw all of the superlatives I can think of at the gameplay, but what is it that makes shooting evildoers in Call of Duty 4 any better than in any of the dozens of other action-oriented FPSs around? Ultimately, it comes down to polish. Everything about the game works together as a seamless whole, drawing players into an experience that proves beyond a doubt that the team at Infinity Ward just "gets it." The simple act of firing a weapon is fun, from the smooth aiming to the realistic pop in your ears and the feeling of impact as your bullets connect with a hapless enemy or send dust flying off of a structure. Missions deliver near-perfect pacing, keeping the story and the action rolling while maintaining a delicious feeling of tension as you await the next suspenseful urban patrol or deafening explosion. And even on the normal difficulty level, enemies will punish you harshly for choosing a bad tactic or leaving yourself exposed, making tactical approaches nearly as important here as in a game like Rainbow Six. 
