I'm going to be honest and say that I really don't listen to a lot of new music, which is bad because I'm supposed to be a "cool" and "hip" blogger that is "with it" or whatever and always be on top of what's NEW. However, I will say that, hands down, my 2012 was dominated by Grimes. "Visions" was mind-blowing and almost every music blogger/writer would agree. I saw her live and she was insanely other-worldly and amazing. I'm pretty sure she's the alien opera singer from 5th Element in a human disguise, or something.
ANYWAY, here's a Spotify playlist (which I only use to publish playlists, which I make obsessively) featuring 20 of my favorite songs from 2012. Again, I didn't listen to everything, so there's probably so much I haven't heard. Everyone keeps talking about Japandroids but I listened to them and they sound really boring to me. I don't know what the big deal is...so that's THAT.