The Naked Scientist - British science show, quirky and always amusing. Bonus points for the super-sexy (nerd girls are totally hot) co-host Kat.
12 Byzantine Rulers: The History of the Byzantine Empire - A history lecture series that recounts the formation through dissolution of the Byzantine Empire through it's key emperors (and empresses).
Archaeology Channel - short sweet updates on what has been discovered around the world.
Background Briefing - From the ABC (Australia) comes this political science program. Occasionally too heavy on the Ausie perspective, it nevertheless is one of the best Poli-sci programs out there.
Big Ideas - Canadian lecture series featuring lots of familiar voices (Roger Gibbons my ex-prof at UofC for one), on a wide variety of topics in international and national affairs.
Carnegie Council - Similar to the Big Ideas program (see above) except American.
Cato Institute Event Podcast - Libertarian and conservative perspectives (and occasionally a Liberal viewpoint) on international and American affairs.
CBC Radio 3 - Best music show period. All Canadian.
CBC Radio: Quirks & Quarks. Best science show period. All Canadian.
CBC Radio: The Best of Ideas - Best poli-sci show period. All Canadian.
Digital Debates (Constitution Centre) - heavy lifting intellectuals lecture on a variety of topics and their relation to the American constitution. Special interest to judicial theory, and the politicization of the SCOTUS.
EconTalk (at Econlib.org) - Economics in theory and practice with heavy emphasis on Hayek and Friedman (sorry Doug).
Escape Pod - Science fiction and science fact program. Often irritating but occasionally excellent.
In Our Time - BBC history lecture series. Recent episodes included a panel of historians discussing the impact to European history from the siege and fall of Constantinople.
Jay Ingram's Theatre of the Mind - If you have an interest in epistemology, neuroscience, or just like Jay Ingram, this is the program for you. Terrific theme song too, 'I can't control my brain'.
Mother Jones Radio - American lefty-progressive news source.
NHL Insider Bob McKenzie - Hockey, hockey, hockey...
Ockham's Razor - ABC's version of CBC's 'Ideas'. Always awesome.
Old Time Radio Sci-fi (I select mostly just the Vanishing Point episodes)
P9 Ambient Electronic - ambient electronic music.
Penn Radio - Penn Jillette (of 'Penn and Teller' magic fame) takes his caustic comedy to the masses. Interesting for his libertarian take on US politics.
Philosopher's Zone (ABC) - The best podcast of serious philosophical inquiry. A tad too heavy on minor English philosophers, and a little too appeasing of the Cartesians, but where else are the subjects even discussed?
Points of Inquiry - podcast of the CSICOP group (committee for the scientific investigation of the paranormal).
Real Time with Bill Maher - because you can never laugh at Americans too hard. Bill Maher was previously the host of 'Politically Incorrect'.
Science & the City - podcast of the New York Academy of Sciences.
Science Friday: Making Science Radioactive - another science podcast.
Science Talk: The Podcast of Scientific American - ditto.
Skepiticality: The Official Podcast of Skeptic Magazine - self explanatory.
SpookyCast - a less rigorous but still interesting philosophy podcast.
The Economist - brief (5-10min) updates on issues throughout the world.
The McLaughlin Group (my dose of political theater) - four US conservative/Republicans beat up on the one liberal democrat, who has the gall to be right. Great fun.
The Media Report (ABC) - a review of global media issues, with the occasional lengthy foray into Ausie specific marginalia.
The Science Show - ABC's science show. Top notch.
Ultima Thule Ambient Music - more electronic wallpaper.
University of Bath Public Lecture - A British (non BBC) lecture series that delves into a wide variety of issues.
Variant Frequencies - hard sci-fi with an ongoing cyberpunk serial.
Voices of Tomorrow - modern sci-fi.
Washington Week - Straight up conservative viewpoint on global affairs. What 'The man' watches to get his news of the world.