Since this is FAVORITE, and not best, I'll just throw these out there, I'm not saying they are the best, mind you, just some of my favorites:
Dudes: Johnny Cash, Nick Cave, Bon Scott, Steve Marriot, BB King, Son House, Gram Parsons
Dudettes: Emmylou Harris, Alison Kraus, Billy Holiday, Kim Gordon
And just for the record, Courtney Hole isn't talented, and Celine Dione is an overrated caterwauler.