I really like Mike & Mike in the morning. I think they present interesting discussion points without taking themselves too seriously. I didn't like Cowherd at first because I thought he was too blunt and opinionated, but he grew on me because he was always able to support his opinions with fact and/or thoughtful explanation.
What I don't like are the blowhards who spew crap for no other reason than to stir the pot and get the listenership all whipped up. Nationally, Jim Rome is one of those guys. Listen to his show and you'll hear that he can fill an entire hour by saying the same thing 100 times. (Sorry, he's not on ESPN.)
Locally (and on ESPN radio), I can't stand Dan Dakich. In some ways he's refreshing because he speaks his mind, but he never knows when to quit while he's ahead. He ends up coming off as an arrogant, condescending know-it-all. And the more you hear him criticize people, the more of his hypocrisy surfaces. Ultimately, I guess he's doing his job, but I think there are more intelligent means of engaging your audience.