I don't tend to follow a lot of video podcasts, mostly since I don't watch tv as regularly as I listen to podcasts. I can listen to audio while waiting for the bus or walking to lunch, but I'm never sure when I'm going to watch tv. Getting a roku has helped, but I still find myself more often going on watch marathons of a tv show rather than watch the tech channels.
Still, I've been watching more and more of Revision3. First started with Ben Heck's show, but now I've been watching Hak5 and also their quick tips called HakTip. (I'll probably try to catch some episodes of Scam School soon as well, but that's a bit of an aside.).
If you're a fan of Security Now over at the TwiT network, I can highly recommend watching some of the Hak5 episodes. Great info on security. I've been watching some of their old episodes on encryption techniques and the inner workings of SSL.
There's also excellent amount of material on linux. The episodes are a real welcome change from some of the more boring tech video podcasts consisting of one guy talking into a camera with some screen capture software.
Currently I'm working through the Linux 101 HakTIp episodes. Mostly it is material I already know, but they're pretty short and a useful reminder of some things I'd forgotten with just enough new stuff to keep watching episodes. If you've always wanted to get better on the command line, they're a great place to start.