Today, I'd like to mention the music group The Wailin' Jennys.
They're a trio of women who sing in tight harmonies, with a folksy, bluegrass style that sometimes delves into British or Irish folk song. I've been listening to them pretty much all day today - they're great for public transit (at least in my opinion.) Arguably, a lot of their music can sound the same if you're casually listening. However, their musical styling and - especially - the lyrics of their songs are both strong pulls towards their originality.
It's great music for winding down after a long day, or maybe mixed in as a part of a road trip CD. They're everything that's good about "just a little bit country." Read more here: The Wailin' Jennys on Wikipedia