Jack Johnson is mood music. He's an OK performer, but I wouldn't exactly call him an artist. His music and lyrics are a little on the tepid side, which is not too say that he's bad. He's just not that good.
I like my mellow a little dark, so Jose Gonzalez is my latest guitarist/lyricist of choice. I do like Feist. I've enjoyed Sharon Jones and The Dap Kings lately.