Similar to The Skeptic’s Guide above, but more silly, Caustic Soda is an awesome, awesome podcast which has quickly become my favorite. It lives up to its name in that the subject matter can get kind of gross (previous topics have included Cholera, Bed Bugs, Regicide, and Leprosy, among other things, and their tagline is “because learning is gross”), but the hosts (and myriad of guest hosts) are great and funny and very well informed.
Also similar lines, Stuff You Should Know is also one I listen to, though I’ve been getting less happy with them over time since compared to Caustic Soda and SGU they’re woefully uniformed and they don’t research their subjects nearly as well. But they’re still decent.
On ‘funny stuff’, there’s the Thrilling Adventure Hour which is, in their words, a “new-time podcast in the style of old-time radio”. Quite silly rotating segments with some awesome guest stars like Patton Oswald and Nathan Fillion.