What about Jim Morrison or Janis Joplin?

I would have to say Hendrix because he was such an innovater. Ever hear about the first time Eric Clapton heard him play. It was long after Clapton had been established as a "guitar god" when he saw Jimi in a little club in London. The next day he sent his manager to find Jimi so he could teach Clapton some new things.

Lennon was great but I think he could have gone on to do so much more if the Beatles stayed together. The team of Lennon-McCartney was a true example of the total being more than just the sum of the parts.

Holly and Marley were both great but I don't see them as really continuing to progress. They might have been the old masters of their genres but not out on the cutting edge.

Never really thought that much of Cobain. I really think he would have just faded out if he fed himself a shotgun shell.