Evolutionary psychology is the branch of psychology concerned with explaining human functions and behaviors in terms of how they increase chances of survival and reproduction. So to the evolutionary psychologist, men are attracted to women of beauty and perfect vital statistics because such characteristics are in fact “cues” — cues that this particular type of woman has a high reproductive capacity as a female. In other words, the woman is highly fertile: smooth skin, shiny hair, full lips and bright eyes indicate youthfulness, and a female of younger age has the potential of producing more children than does a female of older age. The hourglass figure is also more than just a pleasing view of good symmetry and proportion: wide hips indicate the pelvic shape most ideal for childbirth, while ample breasts cue better capacity to nourish offspring once they are born… As mentioned above, evolutionary psychology asserts that as a human being, the true forces that move you to act the way you do are your need to reproduce, have your genes passed on to the next generation, and ultimately ensure the survival of the species. So if you’re a man, evolutionary psychology explains that you select a particular date or potential mate not because you simply find her “pretty” or “sexy”, but because her prettiness and sexiness are indications that she is likely to give you more children—offering you the best chances of having your genes passed on to the next generation and of granting your particular lineage an increased likelihood of continuing to thrive.
I think this ignores the evolutionary perspective that “culture” is the survival strategy of humans. To achieve all that we have, we have developed powerful methods of efficiently teaching vast amounts of information and helping offspring to learn how to find information. Our genes are important. Our memes are perhaps more important. (Not the meme of the Internet but the Richard Dawkins meaning of smallest unit of cultural information.) How we ensure the next generation has access to information such that they achieve even more than their ancestors determines the success of our genes.
Beauty is nice, but keeping in mind the survival strategy, men probably also want a woman capable of raising quality children as well. Someone attentive, intelligent, and nurturing will help offspring achieve their potential.
Of course, a woman much smarter than her male mate probably will find a way to cuckold him. So the ideal mate is both as beautiful as he can manage and about as intelligent.