I don't like his style. He's a pompous blowhard... but that's his showbiz schtick, and its hugely successful for him.
OTOH, I like a lot of his ideas when articulated by somebody more low key and sympatico like, for example, the late Tony Snow before he left talk radio for the Dubya press secretary gig. I used to listen to Tony Snow instead of Rush when they were on the same time slot.
And people underestimate Rush's intellect and knowledge all the time. I've heard him expound on the intellectual history of conservatism with a depth and subtlety that would make Bill Buckley proud. Of course he doesn't often do stuff like that because it would lose his audience.