Chris Cornell is my favorite vocalist. I agree, his voice is the ultimate Rock 'n Roll voice. Of all the people I'd give my left bit to ever work with, he's at the top of that list.
Paul Rodgers definitely has an iconic voice, but Brad Delp (RIP), while exceptionally talented and by all accounts a great person, just never did it for me.
Hijack: I recently discovered that a local guy was Boston's original bassist and quit 6 months before they hit big. Apparently he was the only member who wasn't financially secure (i.e. didn't drive a Jaguar or Benz) and left the band so he could eat. He's done jazz gigs in the region forever, but I recently overheard someone say that he's now quit playing music altogether.. I can't help but wonder if a life feels more empty if you've never really had to struggle to achieve a certain lifestyle, and how much of a factor (if any) that might play in someone's (such as Brad) willingness to check out early. Also a reminder that we're all just people, record deal or no...
John