I'd never heard of Joanna Newsom before today and I can't stop listening to this album. It's such fantastic and beautiful folk music (also the fact that she kinda sounds like Bjork doesn't hurt!)
You might like Jana Hunter, she's in the same vein, think I had her and Newsome on a playlist together.
Blank Unstaring Heirs of Doom: http://www.youtube.com/playlist?list=PLzP5ju1CF_9onb_QXbxhnIISUk917bjmO