The AP, for ther false reporting about a crowd booing at a Bush rally when they learned that Bill Clinton was rushed to the hospital.
http://spinswimming.blogspot.com/2004/09/ap-bias-strikes-again.html
I'll offer up my own scoop on the AP spiking a story on the Swift boat vets' initial press conference on May 4, 2004 because it didn't "further the anti-Kerry Vietnam veteran story any."