Comparison data for US cities

City Data:

By collecting and analyzing data from a variety of government and private sources, we’re able to create detailed, informative profiles for every city in the United States. From crime rates to weather patterns, you’ll find the data you’re looking for on City-Data.com.

This is a very detailed data dump you can use to compare elements of two American cities. Everything from population to education to commuting income. I would have killed to have this kind of data easily available to me when I was in school.