mostly blues, clasic rock, some of the alternative rock, some(very little) country, and even some folk.
folk you listen to for the story. all the rest has to have a strong blues influence to be any good.
My ideal mega concert line-up (assuming the fact that some of the artists aren't living isn't an issue)
open the show with some John Prine, a little folk-country to mellow you out.
then follow it up with Skynyrd, Clapton, Janis Joplin, and let SRV close it down