FactCheck.org A Project of The Annenberg Public Policy Center.
SciCheck Focuses exclusively on false and misleading scientific claims that are made by partisans to influence public policy.
PolitiFact Pulitzer Prize-winning fact-check site.
Snopes Award-winning fact-checking site.
Open Secrets From the nonpartisan, independent and nonprofit, the Center for Responsive Politics, the nation's premier research group tracking money in U.S. politics and its effect on elections and public policy.