I got Guitar Hero a week ago and I have to admit that its very addictive. I play a real guitar, but while the game can be frustrating when the rhythm is off or too artificial, its still very fun to crank through the songs. I’ve found that its also good exercise for my hands- I probably get really lazy playing the real guitar, especial with my little finger and it forces me to work them all pretty hard.
The one other complaint is the controller seems flaky and cuts out when you try to hold longer notes, especially on the middle (yellow) button.
In any case the other similar game, RockBand looks awesome too. Guess I’m going to have to put that one on order. The catch is its very expensive since it includes a controller, drums and a microphone.