99% Invisible - An excellent design/architecture podcast
20k Hz (“twenty thousand hertz”) - great show about the audio that pervades our daily lives, from notification sounds to movie special effects, passing through game sounds, sound history,etc.
Imaginary Worlds - in their own words, “ a podcast about science fiction, fantasy and other genres of speculative fiction”.
All three are done by professionals in their respective fields, exceedingly well researched, and with superb production values.
Was going to post this as well. Just replayed it again, never gets old!