Stuff You Should Know - It's like Wayne's World meets the Discovery Channel. They just present research on different themes.
Welcome to Night Vale - a fictitious community radio station for the town of Night Vale where weird and suspicious things happen.
CBC's Ideas - documentary style episodes on topics in science and social studies.
CBC's Quirks & Quarks - mostly popular and new science.
CBC's Rewind - a look back on older broadcasts and how they covered specific events or themes.
CBC's Spark - kind of like Ideas, but covering more tech stuff.
Nerdist - pure pop-culture. Usually interviews with comedians or actors.
I try not to download too many because I'll get stressed out thinking there is too much I am missing if I don't get caught up on them all! I am always up for recommendations, though.