A few already mentioned Atmosphere, Jedi Mind Tricks, Common, Aesop Rock... not mentioned or missed by me Outerspace, Immortal Technique, Murs, Living Legends, Army of the Pharoahs, Talib Kweli, K-Os... and so many more. I'll link a few videos
https://www.youtube.com/watch?v=WJn6EShMjQ4
https://www.youtube.com/watch?v=RNgjDR1hEv0
https://www.youtube.com/watch?v=E8gIqcQKr1c
https://www.youtube.com/watch?v=yeh6jhHLgtg
https://www.youtube.com/watch?v=RyRB00Xe5-E
If you like any of these people/videos and want more similar, I can point you in the direction of more