FactCheck.org, a nonpartisan, nonprofit organization, is a project of the Annenberg Public Policy Center at the University of Pennsylvania.
Media Bias Fact Checkdescribes themselves as “the most comprehensive media bias resource on the internet" and includes 1000+ media sources in their database.
Politifact is a fact-checking website that rates the accuracy of claims by elected officials and others who speak up in American politics. PolitiFact is run by editors and reporters from the Tampa Bay Times . . .” *
Snopes has long been considered “the definitive Internet reference source for urban legends, folklore, myths, rumors, and misinformation.” *
Sunlight Foundation "is a national, nonpartisan, nonprofit organization that uses technology, open data, policy analysis and journalism to make our government and politics more accountable and transparent to all.” *
The International Fact-Checking Network is a forum for fact-checkers worldwide hosted by the Poynter Institute for Media Studies. These organizations fact-check statements by public figures, major institutions and other widely circulated claims of interest to society.” *

*All descriptive quotes provided by the websites they describe.