I voted 'other', basically because I generally look for much more than one thing in prospective boyfriends.
First off, on initial meeting, it's got to be looks. It's not shallow or superficial to feel like this because it is the very first thing that attracts you to someone, their aesthetic attributes.
Then as you get to know that person their personality becomes apparent, you realise what you have in common and what you don't, why you clicked etc.
Then, I guess you just find yourself attracted to that person as a whole, everything encompassed into one. So it's got to be that women look for more than one thing in a guy. Or at least, most women do.
But a large, or nicely shaped, penis is always a bonus naughty