Its basically if you mixed all the modern shooters and burned them, then took Halo 3 and made it have game sex with the whole call of duty series to make a awsome game baby that occurs inbetween the times of each game.
Also you get to stab people, which is always enjoyable.
Person 2: Nah I'm tired of being killed by 5 year olds, so ima play Call of Duty 4.
Person 1: So you wanna play with rednecks and middleaged men?
Person 2: Hells yes, so I can own them with my young people skillz!
Me: Hell yeah, you know what I'm thinking?
Girlfriend: Ohhh yeahhhh.............
Me: Barret .50 Caliber time bitches!
Girlfriend: DAMN YOU CALL OF DUTY 4, YOU WIN AGAIN!!!1 HaCKzorS!!!
Its probably the most fun game that I've ever played. UAV, airstrikes, helicopters, sweet weapons/weapon add-ons and unlockables.
Jesus - "Buy Call of Duty 4...its the best fucking game ever. I'm already in my 5th prestige!!"
^^Yes, this really happened. That's why Call of Duty 4 pwns.
"You fucking traitor."