If we're talking overall influence, it's Dr. Dre and then everyone else can get far back in line.

Kanye likes to claim that his music wasn't about gangster rap and that's why he was sidelined for... a couple years... meanwhile, Dre not only made NWA and Snoop Dogg but managed to convince the entire rap world that a poor white kid with drug problems and abuse issues was the next huge thing by doing things that nobody had ever thought to do before.