I'd say Brody Dale, from The Distillers... Eventhough Aretha Franklin is of course one of the best singer of all time... But Brody Dale is quite pretty, she was married to Tim Armstrong (Rancid's frontman) so it's class!, and The Distillers are awesome, her voice goes perfectly with the music!
I like Irish women, so I think Dolores O'Riordan is one of my favorites. Other than her I also like Tarja Turunen (formerly of Nightwish). Very similar to Tarja is Floor Jansen of After Forever.
