Social Explorer : Free version allows for online mapping of census data. (up to 2010)
US Census 2010: Interactive mapping from the US Census from the 2010 Census Demographic Profile data.
Esri Tapestry Segmentation : Enter a ZIP Code to see your neighborhoods' characteristics.
Esri's Demographic maps - Use, download and work with maps including various census information.
Esri's living atlas: Maps include all kinds of topics, from global poverty levels to US demographics.
Census Reporter: Quick visualization of Census Data
Knoema: Knoema is a free online data portal that lets you make quick visualizations of data from around the world - data includes Agriculture, crime, education, foreign trade etc.
My Congressional District: Quick and easy access to selected statistics from the American Community Survey, and County Business Patterns.