Nadine Jensen. These other girls aren't curvy enough. The hips need to be comparable to the breasts, or the overall physique is too topheavy for me.

IMO there needs to be a symmetry of upper and lower body. And let's not forget the value of total body voluptuousness. Huge breasts with a tiny torso doesn't do it for me.

Edit: Just saw some more pictures of her lower body. Not a big fan of her legs, not developed enough. A full bodied girl should have strong legs and ass, though not too low a bodyfat %.