I'll preface this by saying that I only recently began listening to many of these.

99% Invisible

Common Sense with Dan Carlin: Interesting perspective on politics.

Data Skeptic: Data science from a skeptical perspective.

Freakonomics Radio

Hello Internet: CGPGrey and Brady Haran talking about things.

Invisibilia: Similar to 99% Invisible but with a broader scope.

Lore: True and scary stories from history.

Note to Self: Discussion about being human in this day and age.

Play Dead: Discussing death in video games. -- This one is very new, and I can't find a proper link for it.

Still Buffering: Two sisters, roughly 15 years apart, discuss being a teenager.

Still Untitled: Adam Savage et al. talk about things.

The Greatest Generation: A Star Trek: TNG podcast by two guys who are a bit embarrassed to have a Star Trek: TNG podcast.

The Minimalists: mnmlsm -- I'm actually thinking of unsubscibing from this one. It seems to be getting a bit repetitive.

The Partially Examined Life: A philosophy podcast for the everyman.

The Skeptic's Guide to the Universe: A show about science and skepticism.

Useful Science: Interesting topics in science.

Waking Up: Sam Harris discusses a variety of topics ranging from politics to science to spirituality.

Welcome to Night Vale: Hilarity and Cosmic Horror combine in a way so beautiful and terrifying that your attempts to comprehend it will thow you into the depths of insanity.