ok they both have advantages and disadvantages, I absolutely hate playing guitar or bass on Rock Band, im just not as accurate with those stupid little bars that replace the circles from guitar hero...don’t get me wrong i can still play pretty much any expert song but its just a pain to get a good streak going. Guitar hero 3 has no drums or microphone, but the gameplay with the guitar has been put to perfection along with super difficult songs...the 3 hardest songs on Rock band are the 3 downloadable Metallica songs, that however does not make up for the lack of extreme difficulty, Rock Band has a huge variety of download songs which im very satisfied with, the best of which is probably “Still Alive” by “GLaDOS”, anyways the drums and microphone along with the larger list of songs makes Rock Band pretty much equal to Guitar Hero III.