Basically indie rap is what 2009 has been about. So basically different, inventive, and progressive rap. Kid Cudi, Wale, K'naan and more have pushed rap from bitches and hoes to deep and meaningful, electro, mainstream and overall amazing. Lots of collaborations and lots of good songs, probably the best song of 2009 Kid Cudi ft MGMT and Ratatat.
Chiddy Bang has made his name from The Cool Catz group to a solo career backed up by Xaphoon Jones crazy beats he is unstoppable.