You guys really lose me with this one. 1/2 his jokes fall flat and he usually comes off as mean spirited. The pitch of his voice often hurts my ears. Hannity seems to die laughing when 'The Great One' calls in, and make no mistake, he is usually dead-on right and pithy, but the bottom line is that Levin is a chore to listen to.
IMO Mark doesn't have time to prepare because of his law practice. Monica Crowley has a good show because she does her homework, and takes the time to book interesting guests.