Everyone who loves football probably thinks about or plays Fantasy Football, so who wants to play Fantasy Rock Band?
Take your favorite musicians and put them in what ever sort of band set up you want. They don't need to be in the same generation, for some funky time travel fantasies.
My favorite would be just a three man band with:
Ozzy Osbourne on Vocals
Geddy Lee on Bass and backup Vocalist
This Drummer Is At The Wrong Gig on Drums
Slash on Guitar