The majority of Guitar Hero III's songs are the original recordings from the honest-to-demigod artists themselves. Previous Guitar Hero games have provided adequate doppelgangers, but when you actually get to bust out a Rage Against the Machine song by Rage themselves, there's nothing like it. The same goes for Weezer, Tenacious D, Beastie Boys, Smashing Pumpkins... the list is near-endless. It's another step in air-guitar fantasy fulfillment.
Hiccups come when some songs (the Killers) feature 15-second bursts where you don't play. A few covers don't do the originals justice: The Dead Kennedys singer is no Jello Biafra. As far as song selection goes, it really feels like the game starts with the duds early (seriously, "Hit Me With Your Best Shot?"), making you work for the good stuff.
The new Gibson Les Paul guitar controller is more ergonomically pleasing than GH2's too-angular Explorer. Its collapsible neck is nice, and button placement virtually eliminates accidental pausing. Being wireless eliminates cord suffocation; just make sure to pick up rechargeable AAs. The strum bar is slightly quieter, but we'd like it to be even more so.