This game is brilliant but make sure you have the hardware to play it!
Now that patch 1.5 made the two expansion packs 'Armored Fury' and 'Euro Force' free, Battlefield is truly a great package. 'Special Forces' is still chargeable but it doesn't add that much to the whole in the end. BF2 is by far the best game in the series. It is the ultimate FPS multiplayer experience in an all-out war. It is not without flaws, though...
I bought BF2 and BF2:SF the next year after they were released, back in 2006. I played the game on a crappy computer and it was awesome and horrible at the same time, because the game demands quite a lot from the computer it is played on. About a year after that I got my own computer. The computer had fairly new parts but BF2 still didn't run the way it should have.
Battlefield 2 is a very heavy game. You need to pack the hardware to play this. Don't be fooled by the release date. You will not be able to play this game on an old computer. I would give this game 9.0 - 9.5, but because of my bad experience with it, I cannot give it a score that high. The game itself deserves the score GameSpot has given it.