1. Atherton, California (Average Household Income: $525,324)

Holding the top spot by a wide margin, Atherton is home to some absolutely staggering mega-mansions. The town is also in close proximity to Stanford University, one of the top schools in the country.

Situated between San Jose and San Francisco, it has become the hometown of some of Silicon Valley’s wealthiest entrepreneurs. Facebook’s Sheryl Sandberg, Google’s Eric Schmidt, and Hewlett-Packard’s Meg Whitman all live in Atherton.