Looking for more songs to complement that Guitar Hero: World Tour purchase you just made? Probably not for several months, but maybe you can do some shopping in anticipation of that -- especially (only) if you really like Aerosmith. Amazon's Deal of the Day knocks half the price off of Guitar Hero: Aerosmith, to a perfectly reasonable twenty bucks. The Xbox 360 version is also on sale, if you would prefer (though obviously we can't endorse such a decision!)
This is the game only, and doesn't come with any guitars or anything, but provided the song list meets with your approval, 41 new Guitar Hero tracks for $20 isn't bad at all.