I've listened to the Hardcore History podcast for a while - it's a history show by a self-professed history fan, who certainly doesn't consider himself a 'professional' historian, and I generally find it entertaining.
The web page (which I admittedly hadn't visited before today):
http://www.dancarlin.com/disp.php/hh Updates tend to be a bit sporadic. Also, I'm not sure how many of the older shows are available for free download, given that they're selling a CD of the things to raise funds.