Battelfield 2 was (and still is) good. It was a nice improvement over Battlefield Vietnam which made it on par with Battlefield 1942 in terms of gameplay. It took many of the gameplay features(?) introduced in BFV and put them into better game.
The one thing I never liked about it was the lack of ammo crates and first-aid cabinets on maps. You had to get team mates to come heal you. It also added the commander role which was good if an experienced player took the role and had a good team calling for support. I never liked playing as it. I would always use one of its tools too late.
Whether it can still be played easily after EA said they wouldn't keep supporting it after the GameSpy shutdown is somewhat worrying.