FactCheck.org is a project of the Annenberg Public Policy Center of the University of Pennsylvania.  They are a nonpartisan, nonprofit “consumer advocate” for voters that aims to reduce the level of deception and confusion in U.S. politics. They monitor the factual accuracy of what is said by major U.S. political players in the form of TV ads, debates, speeches, interviews and news releases.  Fact Check is similar to Politifact in their coverage and they provide excellent details.  The only drawback is they lack the simplicity of Politifact.