Like books you read, it depends on what you enjoy.
I listened to the Passage Trilogy by Justin Cronin and loved it. I also listen to a ton of humour by writers like David Sedaris. I’m in the midst of listening the the new Stephen King book 'Sleeping Beauties". The person reading makes a big difference. The woman reading the latest Stephen King on is brilliant.
Audio books are expensive but most public libraries stock thousands of them. You can download them on your phone with the Overdrive app.
I never read or listen to anything for self-improvement. It’s all about entertainment and escapism for me.