By far, the best places for single men are the large cities and metro areas of the East Coast and Midwest. The extreme is greater New York, where single women outnumber single men by more than 210,000. In the Philadelphia area and greater Washington, D.C., single women outnumber single men by 50,000.
...
One reason young women in the prime marriage years - the 25-44 age range - flock to big cities is to compete for the most eligible men. And smart women who gravitate to vibrant cities are more likely to stay single - for longer, at least - because they rightly refuse to settle for someone who can't keep up with them intellectually or otherwise.

(Richard Florida)