SOCOM 3 is a great game that has very few ways it could be improved.
Sound 10/10
Everything in the game has a sound. Every step you take and every shell that drops has an appropriate sound. The sounds are also well organized so that a shot from a rocket launcher doesn't sound like a footstep on a beach.
Graphics 9/10
There are a few things in the graphics to complain about but they don't stop it from being a good game. I've had a few times to where the frame rate drops, but this is probably just my copy. Also the weapons aren't picture perfect. But overall the graphics are pretty good.
Story 10/10
The story is great. Every mission is thoroughly explained. This title won't leave you wondering "Why am I here?" or "Why do I have to shoot this?"
Gameplay 10/10
The bullets hit something when you shoot it, on both you and the enemy. The weapons behave like their real life counterparts. So don't expect to hit someone 100 yards away with a shotgun, and don't expect to take out a tank with a sniper rifle. The AI is also good they don't spot you when you're 500 meters away. And they don't stand still while you shoot them at point blank range. If they hear a gunshot they'll duck or take cover
Replay Value 10/10
SOCOM 3 has five difficulties, unlockables, and multiple weapons to replay levels over and over.