wow, I'm shocked as to how many people said Guitar Hero. Yeah GH is great, no question, but think about this..Rock Band has a greater variety of songs once you unlock all of them (and if you buy some), rock band has drums and vocals, does GH? nop., Not only that, Rock band also has a guitar to use., Not only can you challenge other people with the guitar, but with the drums and vocals., and think about this, what if you have a couple of friends that want to play, yet you only have 2 GH guitars and you can only play against each other. In Rock Band, you can play with up to 4 people, and not only against each other, but as a band. Enough said. Rock band, by far.