I found myself flicking through some books that I really enjoyed as a kid, and these were the Fighting Fantasy series of books. I used to own nearly the whole set and then gave them away at some point, but I saw some sitting on the shelf at work and decided to give them another go.
I was impressed by how much fun they still were, plus they brought up fun memories of reading them as a kid.
Now I'm not saying the plots are terribly complex, but the idea that the reader could choose how they wanted to approach the story is an interesting one, and trying to bring that to a solo adventure is also an interesting one.
So I'll continue to relive a part of my childhood and enjoy the other books in the series.