The legendary Arthur W. Bell III was the original host of Coast to Coast AM, which is currently run by George Noory, and although retired he occasionally drops in to talk loon (his classic ramblings can also be heard on Dreamland and Somewhere in Time).
In fairness, it might be pointed out that Bell does not necessarily accept all the unhinged claims made by people who call in, and that the point is merely to give them an outlet where they won’t be immediately mocked. But that idea (giving them an outlet) is rather loony itself (and here is why it is troublesome). Although Bell wouldn’t screen callers, he did choose his guests, and must be held partially responsible for boosting the popularity of crazies like Nick Begich, Ed Dames, Richard Hoagland, David John Oates, and Geoffrey Simmons – you can find a list of memorable callers, guests, and incidents here. In 1998, Bell was named recipient of the Snuffed Candle Award. The CSICOP Council for Media Integrity cited Bell “for encouraging credulity, presenting pseudoscience as genuine, and contributing to the public's lack of understanding of the methods of scientific inquiry.”
Bell, who has written plenty of credulous books on the paranormal, is also the co-author (with Whitley Strieber) of “The Coming Global Superstorm”, which was made into the movie “The Day After Tomorrow”.
Diagnosis: Though it is hard to gauge Bell’s actual insanity (though his authorship suggests “plenty”), he is a facilitator for and popularizer of all sort of thorough crap, and his overall impact on the world is surely not good.