If you don't already know Green Day (HOW?) then you must go right now and listen to their music. Also check out Kings of Leon, The Dollyrots, The Strokes, Noah and the Whale, Mumford and Sons, Ra Ra Riot, Birdy, Florence + the Machine, and The Features.
Anything country lol I love country
Not sure what kind of music you like but these are my two favorites, right now :) Fairytale or Bright Eyes by Rebecca Ferguson
The Apples in Stereo
Brahms (Not new but still good ;)
The Dead Science
Bob Dylan (of course)
David Guetta "When love takes over" almost anything by Jack white or Frank Sinatra. Morcheeba. Goldfrapp.
Mickey Mouse Operation by Little People