Not everyone agrees with everything Sam Harris says, but I am a big fan and he certainly makes you think. Here's a collection of episodes from his Podcast that you might like to start with. This is a combination of episodes that I enjoyed, as well as some that regularly get mentioned in discussion forums such as Reddit. You can see all the episodes at https://samharris.org/podcast/
Note: The podcast is now a paid service. It's worth the money if you can afford a few dollars a month, otherwise Sam is very generous in offering a free subscription to those who cannot afford to pay. You can also listen to the first part of all episodes to get a taste of things.
Am I missing an important episode? Send me suggestions using the link at the end of the list.