 I personally prefer nonfiction on audio, especially when it's read by the author. So I'm thinking about memoirs or books that are sort of memoir-ish, usually the author's allowed to read their own. And I like that because I feel like I'm getting some inside scoop about how they've written it. I'm hearing their emotional intonations as they're reading. I also like audio books if it's fiction where there's a lot of plot happening. A lot of decisions have to be made.