Being long enough to rub the very back of my wife's vagina with my cockhead, I must say that her being on top is our absolute favorite position. The cowgirl variants are fine and dandy, but we have a Liberator esse that we use often that makes grinding that deepspot an amazing experience. My wife used to get a lot of UTIs, but now she takes Macrobid and Azo as a preventative immediately after we have our fuckfests. She hardly gets it anymore nowadays.