the incomparable anne briggs of course *sigh*, the holy trinity of sandy, maddy, and june, karan casey, whose voice is like a strong oak covered in white feathers, and, because she beat me to it, kate rusby. would that my albums had such reviews! i'm listening to sandy sing "bruton town" right now. definitely more emotional range than maddy and tim hart's version.
honorable mentions go to christine primrose and linda thompson.