Best online fps ever. Ever.
The single-player is dull it is just basically you and a bunch of bots against a bunch of bots. It is good practice before you go online though to learn the maps and weapons.
Online is 64 player madness with huge maps, stats, rankings, unlocks, and a good number of maps. You can make squads and communicate through VOIP in your squad, one of the best features of this game imo.
Lately all the war fps like CoD, BC2, and now MOHAA seem to concentrate on graphics and effects more then anything. They're all keeping the maximum players to 32, making the games more noob-friendly, and not really improving them each year at all.
This game is legendary for the insane action you can experience online, and for just being an awesome fps in general. Let's all hope Battlefield 3 shows what the PC can really do, anything less then BF2 with improvements will be a real shame.