Agree, this is a great thread. I was actually thinking of something similar to this the other night.
For me in January it was all about this instrumental hip-hop release.
I wrote a review for it in my journal (page 3), so if anyone's interested in everything I have to say about it then check there, but heres the album cover:
For a single song though...It would have to be
Outlandish - Rock All Day, hands down. God knows how many times I actually heard this in entirety. Amazing song.
Also discussed in my journal btw.