Conan has been going downhill for a while. Losing Richter was a serious blow to the on-set dynamic. Conan by himself can be funny, but only when the writing supports him. I don't know all the backstage details, but I would suspect that some number of Conan's original writers have left over the last 10 years, and this could be why the show has slipped into self-parody of late. There was a time when Conan was the funniest thing in late night TV. Now, I'm not so sure (network competition is weak, but Jon Stewart's show comes to mind). There are rumors of Conan potentially moving to an 11:30 time slot in a couple years, and if he did so I'd watch it. With a little novelty and some re-energizing of the writing he could still make a great show.