I view the body as a spirit box (not starting a religious or spiritual discussion) and so believe what is inside to be the most important thing. That said, I nice set of ta's will keep my attention the longest. That would have to be my favorite physical attribute on a woman.

Most woman seem to focus on my eyes, with an occasional glance down. Not sure what they are checking, but I catch it enough to think that there is something there they are curious about.