I was always a fan of the Fighting Fantasy books - they were big in Canada and the UK, but less so in the USA. Interactive role-playing gaming in book form! And dice too!
The later books punished you rather harshly for having it. I think it was intentional so that people with more "powered up" characters (i.e. had been playing since book 1) were given a bigger challenge.
If you're into this series, you'll likely love Project Aon.
Fighting Fantasy books were a much bigger deal the cyoa books for me and my social circle around around that time. cyoa were fun but people I knew were obsessed by FF books. People would lend them to friends, borrow them, trade them, make or print extra sheets for recording stats and rolls. They built an ecosystem around themselves.
I was a big fan of Endless Quest for similar reasons. Loved CYOA, but loved the non-linear narrative along with tracking stats throughout your story.