If I'm looking for a trophy to drape my arm round for a night out, maybe I'd go for stunning looks. If I'm looking for someone to have a relationship with, there'd be a whole series of factors (sense of humour, sense of fun, good intellect, good education, reasonably assertive, and so on) that, essentially, boils down to "personality".
While I wouldn't necessarily be interested in anyone nauseatingly ugly, to me, looks, come a LONG way down the priority list in picking a partner.
In fact, come to think of it, even for a single night out or a one night stand, I'd rather have someone that was plain but fun and interesting, rather than a gorgeous but vapid airhead. A partner, to me, is more than eye candy, even if it's just for an evening.
I agree with Kell_ee : a relationship based on looks alone won't last. For that matter, neither will the looks. Time, and mavity, tend to do their thing and the fact that it seems it does it much more harshly for women tends to say something nasty about society and our perceptions.
Oh, and as it happens, I seem to have acquired a wife who fits my "personality" requirements perfectly and, in my eyes at least, is gorgeous too. What everybody else thinks of her looks I neither know, nor care.