I'm kind of torn on Ron Paul. I agree with a lot of what he says, but he suffers from the same delusions that many Libertarians do, which is that political ideology has to be pure to work. Hell, Republicans and Democrats both occasionally get things right.
I do think he has integrity. I also think it's worth noticing that it's an easy thing to have when you know there aren't any consequences. He can vote against spending bills because his general philosophy says to, but he also knows that they'll pass anyway. He certainly understands the game. Attach expenditures and earmarks for your district, and then vote against the bill!
What I really do appreciate about him is something I read a while back from a former Republican Whip, who said that there was a general understanding that you could crack any heads necessary to get a bill to pass, but leave RP the hell alone. Nothing you're going to do will persuade him, so spend your efforts elsewhere. I wish there were 500 more people like that in Congress.