This is a surprisingly easy question. The answer is ALL KINDS of books.
While growing up, I went through phases in my life when I would read only a certain type of book. As I've gotten older, I've realized that I read books for lots of different reasons.
So, yes, I enjoy being entertained, and I like to read books that are (primarily) entertaining. But I always like to learn new things, so I also like to read non-fiction books about subjects that I want to know more about. And I love good writing, so sometimes I like to read a book that has beautiful writing.
The act of reading can be different for different kinds of books. I was an Engineering student. When reading a technical book, the reason to read it is to increase your knowledge. So you need to read it SLOWLY. You need to make sure that you understand EVERYTHING. And you need to be able to recreate most of the equations that are used.
But when reading for fun, you can read quickly. The idea is to absorb the story itself, and this can move fast.
On the other hand, when you read beautiful writing, you should savor it. This can mean to re-read parts of it, and to go back and dissect sentences to think about the structure of the author's thinking. When you savor writing, it shouldn't be done too quickly.
I've found that since I've aged, I seldom read one book at a time. Now, I usually have 4-5 books on my end-table that I'm reading. I switch around as I go, depending on my mood. As I sit here, the books on my end-table that I'm reading are a thriller, a book about chess, a comedy, a book about thermodynamics, and a book written by a chef in which he tells the story of his professional life. They're all interesting. And they're all very different.