When I think about effective storytelling, part of the difficulty is holding one’s attention. The first task is to craft the story well, but to make it more effective you have to find an engaging medium.
For me, the most engaging medium is the podcast. Because of the way people engage with this type of content, there are usually minimal distractions. Whether it’s while cleaning dishes or sitting on a bus going somewhere, it’s a type of content you generally listen to when you can focus intently.
On top of that, the medium is very intimate. With the right quality of sound engineering, it creates a very close space where the listener feels as if the narrator is speaking to them directly. If you want examples of programs which I think accomplish this very well I would say:
99% Invisible
This American Life
Startup
Planet Money
Just to name a few.