I listened to one of the first ever TWiT podcasts back in the day (and have listened ever since) and thought it was the future then, so glad to hear it's taking off properly.
Apart from TWiT network podcasts I like to listen to:
Stuff You Should Know - So awesome, I'm a late convert to this from a few years ago. Chuck and Josh are the best!
DTNS - Tom Merritt is great, really insightful. Some of his guests leave a little to be desired (Patrick Beja is great though).
The Packet Pushers - Awesome in-depth networking knowledge.
Dr. Karl on TripleJ - Only the best science explainer in the world, ever.