The best podcast experience I had in 2017 is You Must Remember This: Charles Manson's Hollywood. It was not recorded during the last year, but it was then that I discovered it.
This is a hard subject. Disturbing and dark story, developed 12 parts, following people and events around Charlie Manson and his cult.
Storytelling is superb. Host, Karina Longworth, is very creative and not only that she is good at writing the story, she is also flawless in presenting it. After listening an episode, I could hardly wait to hear the next one. She spends a lot of time explaining the zeitgeist of the late 60s, which was specially interesting to me due to the fact that I didn't know much about that period of American history. There is a lot of music, the Beatles mostly of course, and it helps to feel the story, not only to understand it. You will never look at the hippie culture the same again.
Story itself is complex. I was unaware how deep it went, and what it meant to the people of that age, or how misogynic Roman Polanski is. As an added, and unexpected, bonus this series gives one of the best descriptions of how cults are made and maintained.
You don't have to be a fan of celebrity stories to enjoy it. And I am not. But, you will enjoy this. It is pure gold, and if there were podcasting awards, I'd vote for it.