Mission to Zyxx is an improvised science fiction podcast, just like the website says. They improvise all the speech and the action, but then they go in after and clean it up and add awesome music and sound effects, and it comes out really good.
I was listening to one on my walk yesterday and I was laughing so hard I thought I was going to pee my pants right there on the trail.
It's not really that obscure, I don't think, it's just pretty new. Season 1 started last August, and we're about halfway into Season 2 (assuming both seasons have about the same # of episodes).