He's a demogogic, faux-populist blowhard and a self-serving phony. I used to love the guy, but O'Reilly's Howard Beal act has worn thin. It's all Me-me-me-I-I stuff. The show's become a laundry list of things that he's outraged about, so we too should be outraged about it. Every show he barks out another urgent proclamation that Bush or government, or Hollywood, or the music industry, or corporations, or society, or people who drive SUVs MUST ACT upon his demands or our whole nation faces dire conseqeunces ... blah, blah, blah.
He's big on bitching and moaning and short on solutions. He's terrific when he knows his subject, but he's a dismissive and interruptive jerk when confronted with guests who know more than him about a given subject.
He's worth listening to for maybe 5 minutes an hour. Unfortunately you don't know in advance which 5 minutes.