PolicyMap data on demographics, income and spending, housing, lending, quality of life, economy, education, and health. Can be viewed on the census tract level in many cases, as well as zip code, city, county, and state.
Social Explorer data maps with built-in, up- to-date data on demography, economy, education, land-use, environment, business, crime, health and much more.
data.census.gov
Demographic and economic data from the U.S. Census Bureau