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: Veronica Leal, Autumn Falls, Aaliyah Hadid, Lana Rhoades, Brenna Sparks, Katie Morgan, Monique Alexander, Rae Lil Black, Nia Nacci, Little Caprice, 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.