Jason Mraz, Ben Harper, John Mayer, The Shins, Cake, Flaming Lips, Florence and the Machine, Kings of Leon, The Low Anthem, White Stripes, Everything is Energy, Regina Spektor, Deftones, Queens of the Stone Age, Boards of Canada, Damien Rice, Colbie Callait, Gavin DeGraw, James Morrison, Bon Iver, Phoenix.
Extrapolations of those might include Postal Service, Jamiroquai, Yeah yeah yeahs, My Morning Jacket.
Softer sides of those might include David Gray, Michael Buble, Elvis Costello, Cat Stevens (Youssef Islam), William Fitzsimmons, Gregory Hoskins, Sera Cahoone, Dar Williams, Iron and Wine, Rachel McCartney, Ray LaMontagne, Tallest Man on Earth.
Plug those into Spotify or Pandora and you'll get buttloads of good stuff. I edited and italicized the ones that I particularly recommend.