Imagine Dragons is amaaaazing. You'll be glad you 'discovered' them for many, many years to come.
As Quercus mentioned, AWOLNATION is another awesome artist - one of my absolute favorites. This video is actually how I first heard of it: (watch it, its hilarious) I had to listen to the rest of the song after that, then I went on to listen to all the other songs. 'Kill Your Heroes' is another one of my favorite songs by AWOL.
Another band I adore, and recently got into, was GroupLove. Named my journal after one of their songs, Ways to Go . The music video for this is just brilliant and the absolute feeeeels the song gives you...
This song has been my obsession lately; I turn the volume up every time the radio plays it:
Let's see... there's also Passion Pit, Fun, The Lumineers, Mumford & Sons, Of Monsters & Men, Ed Sheeran, Passenger, and so many more that I can't name right now. But yeah... that's my general taste in music!
Oh, and one more! Bastille! Love this song!
Hehe, another song! As you can tell, I love music! I already mentioned Passenger, but this song is just too beautiful not to share: