In no particular order.
Firefly Talk:
http://www.fireflytalk.com/
The Signal:
http://signal.serenityfirefly.com/
Escape Pod:
http://escapepod.org/
Various podcasts and podiobooks by Mur Lafferty: www.murverse.com
Ask a Ninja:
http://www.askaninja.com/
The Bitterest Pill:
http://www.danklass.com/pill/
Radio Free Burrito:
http://wilwheaton.typepad.com/
Tales from the ‘Verse:
http://www.talesfromtheverse.com/
