If you really must limit our choice to female idol and no male idol, I would choose Sally Yoshino in High School Girl Confinement and r*** in Turn (SHK-063). Very convincing performance, especially considering it's all fake penetration. I wish to see newer movies with performance like that. There were others I downloaded from KaZaa/Morpheus back in the day, but SHK-063 and Sally Yoshino was the only one I was able to identify.