Add me to those who voted for the woman on top position. To me the only disadvantage is after I have a climax but, all the more incentive to not have pre-mature ejaculation!
The rear or 'doggie' is good for penetration (my second choice) but, I truely enjoy the facial expressions on my lover's face as she has an orgasm. That you don't see from behind.
My third choice is me on my knees, my lover on her back and, her legs in the air resting on my shoulders.
Adrian