There is no argument about this as of right now you want to compare numbers Andre Nickatina is the biggest rap artist out of san francisco hands down in the 2000s. His concerts bring in 1000 people plus each time he performs he has a huge college fan base. Not to mention he also sells records still on his own label 20k plus units sold without a big time distribution. The roots had Nicky perform with them in New York city a few months ago.
San Francisco has never had a rap artist have a gold or platinum album. But over all Rappin 4 tay would have been the biggest in the 90s with players club, he has a verse on TWDY players holiday, and was on Tupac All eyes on me. Not to mention 4 tay was also nominated on the real deal MTV music awards for best rap video with ILL BE AROUND.