I have been a fan of the rhythm-based music games since I first played Guitar Hero. It was right around the time I started at NI and my buddy Tom tipped me off that GH was something I just had to try. Dave, Slaughter and I all went in on the purchase, and it was all down hill from there. I don't think any one of us got the proper amount of sleep for the next week or so as we tried to beat the game on Medium, then Hard, and finally Expert. Good thing there was plenty of Sparks. Since then I have come to grips with my GH ability, which I classify at just at pretty good (mostly because my fiance is much better at it than I am), but I remain dedicated to my support of Guitar Hero. I even dressed up like characters from Guitar Hero for Halloween last year (see evidence to below, bonus points if you can guess which characters).
When Rock Band came out I didn't jump on the bandwagon as quickly. In fact I still haven't purchased the game, however I did get Guitar Hero Aerosmith (which I have beaten and enjoyed). I think the hesitation came mostly from not wanting to buy the drums, which I had heard were not to snuff terms of quality. Plus there are always more games than I have the money for. In any case, that was the uneasy state of affairs from the two competing guitar rhythm games from my stand point. That is until I heard about Guitar Hero 4 (World Tour) and Rock Band 2.
So now I have two different full band simulation games coming out in a few weeks. So which one do I get? Rock Band comes out first, but GH looks like it has better quality instruments. That's where you Hop Ons come in. Let me know in the comments.