The BBC has an excellent history of ideas program called In Our Time that airs weekly and is hosted by Melvyn Bragg. Bragg usually moderates a discussion of a topic in history, culture, philosophy, religion, or science by three guests, who are usually academics from universities in the UK.
Last week’s program featured a good (albeit introductory) discussion of the ontological argument from Anselm to Plantiga by way of Descartes, Leibniz, et al. by John Haldane (St. Andrews), Peter Millican (Oxford), and Clare Carlisle (King’s College London). You can download the broadcast and listen to it at your leisure.