Really makes me miss Firing Line, where most interviews were an hour and an occasional one (Malcolm Muggeridge, I seem to recall) went two. Yet absolutely riveting.
I seem to remember Mortimer Adler getting a little testy with Moyers' slow wits at times, but never, of course, with Buckley. And Adler was testy, generally.
The best in-depth segments are on Brit Hume's Special Edition program on Fox News. He'll delve into a subject/topic with a well informed guest and when the interview is over, you actually are move informed - and it isn't a rah-rah for the Right segment either.