Definitely Andrea True,who beat out both Marilyn Chambers and Traci Lords as the first crossover-from-porn-to-the-mainstream star.
Wendy O. did "Candy Goes To Hollywood" and a few live porn shows before singing for the Plasmatics(and becoming Rock N Rock's Queen Of Destruction),and Madison's music careers only consisted of L.A. nightclubs,despite two B movie appearances(they being "Naked Obsession" and "Evil Toons").