I believe The Beatles: Rock Band came the closest to being perfect. Eveything about that game was just beautifully done and the only things missing was Pro Drums, an option for Keys, and a few more Beatle songs (Hey Jude, Strawberry Fields Forever, Yesterday etc. etc.)
I wish they ported the changes they made to the ipad version to the desktop one, and also made an android version. The game is damn near 100% playable as is on a touchscreen, there just needs to be a way to pause.