it says "bay area artists" on the thread, but if u want to limit it to just rap, then its tupac, then hammer. pac sold over 30 million and hammer over 25 million. tupac may have been born in ny but he claimed bay till the day he died. he was and will always be bay. he lived here and got his start here. he never forgot his roots.
as for game, he may have got his start here, but he always claimed compton, not bay. tupac is the biggest bay area rapper of all time.