Historian and libertarian Ralph Raico. Source of photo: http://en.wikipedia.org/wiki/Ralph_Raico
If you’re looking for a wise, witty, erudite, and thought-provoking discussion of a variety of historical issues from a broadly libertarian perspective, then Ralph Raico is your man. (The flavor of libertarianism is neo-Austrian, but not dogmatically so.)
Several of his lectures can be purchased on CD or cassette from the Ludwig von Mises Institute. Or you can listen to streaming versions on your computer for free.
I particularly like his lecture on "The Industrial Revolution" in which he persuasively argues that ordinary people benefited from the Industrial Revolution, and that the benefit would have been clearer sooner, had it not been for the coincidental costs being imposed on ordinary people by the Napoleonic wars and by the corn laws.
The link for the free streaming version of the lecture is:
http://www.mises.org/media.aspx