1. Answer: It depends on everyone's taste and these rankings change all the time. According to RankMyPorn, at the moment, the top ranked Bisexual Female Pornstars in the world are: Mia Malkova, Lana Rhoades, Veronica Leal, Kenzie Reeves, Kayden Cross, Riley Steele, Elsa Jean, Sasha Grey, Katrina Jade, Eva Angelina, but these will change based on what people vote.
2. Answer: It changes. You can see the latest rankings on RankMyPorn.com and also vote on it for free.