El-P & Killer Mike
El-P crushed 2012. Between his own album and his collaborations, he proved that not only is he still relevant, but he's still one of the most forward-thinking artists in hip-hop. It shouldn't be a surprise to anyone who's followed the rapper/producer throughout his career, but it was still refreshing to see him making some of the best music out instead of fading into indie rap obscurity like a lot of the underground hip-hop acts from years past. His finest moment in collaboration, and one of the best pairings of the year, had to be with the often underrated vet, Killer Mike.