The most biased is probably Bill O'Reilly. This is the same guy who denied belonging to any party and wasted an entire interview he got with President Obama to criticize him for the failed launch of the ACA website and the "conspiracies" of Benghazi and the IRS. Of course, that was all done to appeal to his conservative base and ignore the issues just to attack Obama. He's almost like President Bush. He goes on and on never to actually make a point even when it matters most.
He also (twice) knowingly and falsely attributed
Nazi war crimes to American soldiers to try to downplay atrocities committed by American soldiers in Iraq.