What music am I missing out on?

I feel that the music I am exposed to is restricted to what's on the radio or MTV, basically mainstream music. So I'm looking to broaden my horizons. I'm looking for good, catchy music along the lines of Sound of Arrows, Bon Iver, Coldplay, Florence + the Machine, Mumford & Sons, Regina Spektor, Snow Patrol, U2 and Vampire Weekend. Electronic, indie, rock, I'm interested. Can anyone help?