An amazing game that's amazingly well put together.
The multi-player will last you forever as you'll keep coming back to it. The nice balance of the game and the large selection of weapons and customization is something to brag about.
The game is well put together and has no major or minor flaws that take away from its value. The only thing that could be done to Call of Duty 4 is improvements, not bug fixes. Too bad Call of Duty 5 is being done by an entirely different team.
The game is something that would sound too good to be true if I were to explain it in detail so take the advice of the many 9 and higher player ratings and buy the game!