[tony]

I'm biased in favor of audiobooks since they fit with strolls. Books are for sitting, walking burns calories :)

Books:

How to Win Friends and Influence People and How to Stop Worrying and Start Living by Dale Carnegie

Taste testing:

PhilosophersNotes is like sparknotes for self-help books. Can be used as a way to discover / screen books you'd like.

Audio:

Psychology in Seattle's episodes regarding Attachment Theory (6 episodes). The reason why is it's a swiss army knife for understanding relationships and behavior. These episodes are paywalled though, but there are free episodes available if you use a Podcast app.

Like aphextron mentioned Socrates: Republic, Apology by Plato are really good. The one narrated by Ray Childs.

Audible for Zen and the Art of Motorcycle Maintenance by Robert Pirsig (it's like a Socratic dialog about what Quality is)

A lot of stuff by The Teaching Company / Great Courses in general have been good quality (maybe I've been lucky).