Used 2 tracks of this album (Distant Relatives) by Damian Marley and Nas already in the Nas post. Mixing hip-hop with reggae which was very nicely done if you ask me.
Nas & Damian Marley - Nah Mean
Nas & Damian Marley - Tribes at War
Masta Ace, a straight genius:
Masta Ace - Too Long (feat. Apocalypse)
Masta Ace - Big City
Some random great tracks,
Life MC from Phi-Life Cypher. Phi-Life Cypher as an underground hip-hop group from the UK. Definately worth listening to.
Life MC - Bomb Propaganda
Phi-Life Cypher - The Racists
Life MC is known for being a freestyle genius, check it out here
Life MC - 10 Minute Freestyle