I am a big fan of Mark Greaney's Gray Man Series.
I have consumed all of them using Audible.
These are the books in order (I do recommend listening or reading in order if you can. However, they do stand alone if want to listen or read them out of order).:
- The Gray Man
- On Target
- Dead Eye
- Back Blast
- Gunmetal Gray
- Agent In Place
- Mission Critical
- One Minute Out
Here are several reasons why I enjoy them:
- Court has a moral compass.
- The moral compass gets him in all sorts of unintended consequences.
- It is action packed.
- It is fast moving.
- The story telling is exceptional.
- The locations are well researched.
- I like action spy/espionage/intelligence/special operations/covert/clandestine/etc. stories.