From what I've read the features men across cultures find attractive are, in decreasing order of importance:
wide hips - good for child bearing
relatively thin waist - definitely does not have to be thin in absolute terms, just enough to make the hips and breast shapes noticable. Men prefer an hourglass, not stick figure.
firm/shapely breasts - large is typically preferred because it is easier to determine if they are still firm and shapely. Large and saggy is worse than small and firm, but since large breasts sag sooner shapely large breasts better indicate youth and health.
fair skin - women are naturally slightly fairer than men, are fairer still when young. Although modern western culture puts forth tan as an ideal, men almost always naturally prefer skin that is naturally on the fair side for the girl's ethnicity. (Racial differences are not too hard to filter out, so a fair skinned black girl may still be preferred to a still lighter but heavily tanned white girl.) Women do not in general care about male skin tone. It is hypothesized that the main reason Europeans are so fair skinned is not so much because of environmental factors in and of themselves but rather that the harsh ice age environment encouraged monogamy, as it was more difficult for a man to provide for many wives. When a man can choose only one wife he tends to choose a fairer woman and only fairer women pass on their genes, but in polygamous societies most women of all skin tones get the chance to reproduce.
light eyes - not a factor in many ethnic groups, but this is another indicator of youth which can also mark sexual fidelity. Certain hormones released during pregnancy cause a woman's eyes to get slightly darker, so very light blue or gray eyes can are associated with virginity. Blue eyed men show the strongest preference for blue eyed women, probably because the recessive nature of the eye color genes mean that eye color can be used to help determine if she is bearing his child or another man's. (Technically it is not strictly recessive as there are at least 5 different genes controlling human eye color and some gene combination that allow two blue eyes parents to have a brown eyed child, but these are very rare and so do not really influence Evo-psych.)
(fair hair is not naturally preferred, but does tend to correspond to the preferred eye and skin tones.)
