I have to recommend The History of Rome podcast anytime I have an opportunity. Mike Duncan does a great job "storytelling" the history, and is very up front about what should be accepted as relative fact (strong sources) vs. the more uncertain elements from the more questionable sources. It's great if you're driving a lot.
Thanks for the link. I also recommend Hardcore History[1], by Dan Carlin. He recently did a series on the fall of the Roman republic, which I liked a lot. Dan Carlin also has a political podcast titled Common Sense[2], which is also very interesting even if a bit US centered.
http://thehistoryofrome.typepad.com/