What game has the best audio

VVVVV

Battlefield: Bad Company 2.

Grand Theft Auto Vice City: Old Audio

The Sims. The sound effects from everyday activities are hilarious and the background music while you're building your house is so rich.

BioShock Infinite had some great audio.. NBA 2K12 had a great soundtrack.. XD

NieR or Okami are the best. Bayonetta also has some good music.

SimCity 3 and 4, Evil Genius, Civilization IV, Tropico 3 (and presumably 4).

Alan Wake !

Golden Sun :)

Duke Nukem 3D

Proof

:D

fallout 3. Great atmosphere. Billie

Dishonored

Bastion

Hotline Miami

Half-life 2 had some pretty awesome audio, like this and this

That's a difficult question. I think Red Orchestra 2 has the most realistic gun sounds.
Music... well, a lot of games have good and even great soundtrack, but it's difficult to choose just one... but I think the one that really, and I mean really added to the atmosphere of the game greatly in a specific parts of it and did not exist just as an amazing soundtrack, but also was a part of the gameworld was the music made by Kai Rosenkranz for Gothics, especially Gothic and Gothic 2 NotR (not the Gothic 2, but the music in the expansion world).

Exploring Jarkendar with this kind of soundtrack was an unforgettable experience for me, even though it's just a game
http://youtu.be/z9O_naB_4dU

The game also had great Polish translation and voice over. Too bad the English translation wasn't good, so people not knowing German/Polish got a botched game :p