Am I the only person who hates the Avett Brothers? I just have never been able to get into them. Saw them pretty early on, summer 2008, at a beer hall in Troy, NY, and thought, well, these guys are going to be playing free shows at drunk college picnics for the rest of their lives. Oops.
On the female side, Joseph, I just remembered Tift Merritt. Beautiful voice -- closer to true old-school country. Shelby Lynne as well, though she's a little poppier, but boy can that girl sing.
I mentioned the Milk Carton Kids, and though I know I've pimped them on this board before, their albums are both downloadable completely free at their website. They're terrific.
edit: this song, it kills me.
The Milk Carton Kids - Girls Gather Round - YouTube