I've never had so close to reality driving simulation experience as with GT5. You need a wheel to grasp the reality!
If you plan to play with controller - don't waste your money and better get Forza 3 - its more arcade than GT5.
GT5 is REAL DRIVING SIMULATOR. Thats why its called like that - it feels as close to real driving as it can get if you have proper equipment to play the game.
Songs are ok, not the best selection there can be, sounds are as close to real as they can get - again if you have a good sound system. I haven't tried 3D yet but it looks like in 3D game looks even better. I mean there is already not much to go to make it better but 3D still makes it more visually stunning.
This game will create mixed impressions as people who has no equipment to play it and just a controller will most likely hate the game. This is easily the best racing game of this year and of the decade. Some people may compare it to Forza 3, which is good and I played it for a while myself, it has great customization options etc. But GT5 is a solid rock of driving simulation and in this game they've achievemed as much as there can be achieved.
Don't listen haters and nay sayers. They base their vague opinions on ignorance and frustration. 1000 cars and 200 only premium? All the cars look great and have a great detail. Premium cars have a cockpit for them that you can change to and real physics base damage. The rest of the cars they are pretty much like "trash mobs" in MMOs. You play GT5 to eventually advance in levels and win-buy as many premium cars as possible. Premium cars they are your raiding gear. But I'll repeat myself again - it doesn't mean that the rest 800 cars are worse. They just don't take damage and have no cockpit camera.
I personally play with Playseat and Driving Force GT wheel and I rarely use cockpit. When you play with a wheel in front of huge TV you rather want to see the cars hood since you already sit in your own sort cockpit. Cockipts in premium cars are made to just enjoy the visual fun of your premium cars on display stage.
GT5 is a must buy. No question there. If you have a wheel and maybe even a playseat like myself - GT5 is your best option to enjoy driving as close to reality as possible.