Body dynamics. Movements, gestures, mimics - all the three components come over me like a waterfall.
Whatever stands out. This could be good or bad things. That said, I am instantly attracted to men who smile a lot. A great smile would have me looking longer than I should be looking.
There is nothing more enchanting than a good voice. Voice is almost a kind of deal breaker for me. I might physically look at any part first, but I always wait for her to open his mouth till I judge.
A good voice, although not completely quantifiable has a certain ring to it.