I haven't been a big fan of G4TV since the TechTV marriage - not that I've watched them much.
But last week I came across the Brainiac Thermite Segment, and a quick search showed me that G4 is showing episodes of Brainiac. I set the TiVo to pick up episodes, and we watched one last night.
Great show. A little bit like Mythbusters, but a little more science oriented.