The main stuff I don't like that Art covers are the religious themed shows (ie Who or What is God? Reincarnation, asscended masters, etc) - I like when he interviews the God Particle guy (and the like), but that's more along the lines of hard physics than soft religion..
By far my favorites are the kook science ones and Old School Conspiracy stuff.
Actually, as far as religion goes, I do enjoy that Giants guy - but he seems to be more a guest of Noory than Art. I actually bought all his Giant books last year (on a whim). They were interesting.
Bigfoot = Tired
Chupacabra = Wired
Philadelphia Experiment, Time Travel Theory, M. Kaku, EVPs -- totally rock.
There was a great show a while back, I don't remember if it was Art or not - but the guest was this guy ranting about the horrors of drinking milk, which he called Cow Pus. He had me convinced for about 24 hours that I should never drink milk again, it was such a wonderfully gross show

Has Art ever interviewed
Robert Anton Wilson?