Their newest didn't really sell me, but a lot of the music I listen to frequently is sort of a slow burn (I didn't even start liking the latest Jonathan Coulton album until it's 3rd or 4th listen-through).

Mike turned me on to Alt-J. It's like Fleet Foxes and Band of Horses made a band, broke up, faded into the shadows, and then were re-discovered by an all-hobo cover band 15 years later. Pretty enjoyable.