best rock voices

This could be a long list if you want to include the entire history of rock. Some possible nominations might include:
Elvis Presley; Chuck Berry; Roy Orbison; Jerry Lee Lewis; Jim Morrison; David Clayton Thomas; John Fogerty (the lead singer for CCR); Janis Joplin; Mick Jagger; etc. Can you narrow your definition a bit?

If we include doo-wop, R&B, the MoTown sound, the California surfer sound, etc., as part of rock history, we then need to include a lot of other candidates for "best voice". I propose that we revise the thread to better define the categories of rock, and then choose the "best voices" in each category. Here the link to the Rock 'n' Roll Hall of Fame that lists all of the inductees:

http://www.rockhall.com/hof/allinductees.asp

Any suggestions for categories?