Underground Rap.
Stadistik has been around for a long time, but the best no.
Look up a guy named Astronautilus on youtube, he is amazing, for shows he has the crowd pick topics and he freestyles off the top of this head and it sounds like its a verse strait off his EP.
I've been to his show and I will never listen to mainstream rap ever again I was blown away.
Also Atmosphere, Brother Ali, and P.O.S.