Originally Posted by Goofle11

Good list there Sparky. I would add the following:

Lushlife
Bigg Jus
Big K.R.I.T. - Not so much "underground" any more, but whatever.
Billy Woods
Quakers
THEESatisfaction
Cunninlynguists
Elzhi
Mr. Muthafuckin' eXquire
Killer Mike

Also, if you wanna use You Tube to keep up with new Hip Hop artists, look out for Dead End Hip Hop, and for general underground music (with a lot of Hip Hop) check out theneedledrop.