REF DESK
Refdesk.com is the complete fact checker on the web with links to more reference websites than any other single source. Just keep scrolling down.
FACTCHECK.ORG
Fact Check.org is project of the Annenburg Public Policy Center.
Like everyone else, their opinion is subjective. If you want to know the politics of a foundation like the Annenberg Foundation you should know who their Directors are and who they give grants to. Like their recent grants to the Woodrow Wilson National Foundation or Human Rights Watch, Inc.
From FactCheck.org: Cash Attack: 2010 Players Guide Judge for yourself.
CHARITY NAVIGATOR EXAMINES CHARITY TRUSTS
Search by charity name or charity interest. Top ten lists also include Top Ten Celebrity Lists. You can view most data without being a registered (FREE) user. For instance, their operating revenues and expenses. Like PETA. Others with four stars might be flagged with an advisory about current legal investigations.
Some are just plain interesting like Americans United for Separation of Church and State.