top 5 rappers
Ghostface
MF DOOM
Kanye West
Nas
Lil Wayne (Carter III era)
top 5 producers
Dr. Dre
RZA
J Dilla
The Neptunes
Kanye West
honorable mentions:
producers
Alchemist, DJ Premier, MF DOOM, Timbaland, Just Blaze
rappers
Scarface, Black Thought, Andre 3000, Mos Def, Big L