You beat me to it. This guy never reached the heights of stardom as the others which have been mentioned. A brilliant vocalist, just as good live as recorded. I think I read somewhere that he cited Paul Rodgers as one of his main influences.
When you go to live gigs a lot, its sometimes hard to make the separate between great singer and great frontperson for the band. It becomes more like, vocalists that can make the hair stand up on the back of your neck or bring a tear to your eye, often both in the same song. Many have been mentioned already, but for me: Women Ann Wilson Annie Lennox Taylor Momsen Magali Luyten Men Freddie Dio Glenn Hughes Dave Meniketti (Y&T) Russel Allen (Symphony X)
Bonn Scott Joe Elliot James Hatfield Brian Johnson Women Joan Jet The bird from Heart The bird from the Bangles