This discussion could go many ways -
If it wasn't for Grandmaster Caz, would we have Rapper's Delight?
Afrika Bambaata took dudes from the street and formed a true movement with hip-hop as the backdrop.
How many artists came from under Dr. Dre's influence?
Master P is the reason the South broke through on a mainstream 'acceptance' level.
James Prince has been holding down the South throughout hip-hop's history.
You can take a 3 credit course of the Life and Times of TUPAC SHAKUR.
Russell Simmons? Lyor Cohen? Rick Rubin?