Most Helpful Guy
There are two antropological answers to this question.
The first refers to patriarchy, herds and alpha males controlling both all the fertile females, and the beta and omega males. This dates back to our most primal instincts as primates.
The second one is more darwinian. Males find attractive females that visually speaking seem more fertile, hence why we mostly prefer younger women, proportionate hips for giving birth and proper, firm breasts to feed the descendants. This last one, as societies evolves and social human interaction slowly differs from sole primal instinct, has nowadays interferences from social pressure (either from religion, advertising, and all in all media in general). Anyway the primal instinct is still prevalent in some different degrees, depending on the male, his social environment, his intellectual skills and his grade of maturity.
When this two factors are overcome then males like me start broading our spectrum of possibilities and find attractivenes in more sutile details or even devolpe new tastes in our physical evaluation of women - as a matter of fact we start to also evaluate other psychological aspects. This again is the survival of the fittest, since being in a commited relationship will require this grade of mature to ensure a high rate of success (from both parts).
On a much more simplistic level, when I was in my young years, I wanted to get the hot chick because: (1) she arosed an elevated sexual appetite in me that could also be confused with feelings of romantic love (without the need of any social interaction with her) and (2) if the goal was achieved, that gave me rewards in my social position of popularity in the then immature herd of teen males. (And beware, many men live in that immature status refered in point two for their entire lifes).
Most Helpful Girl
They don't go for the ´hot girls´. They go for those who attract them. What attracts the other, might not attract someone else.