I don't know, but at least I know that someone else doesn't know either. I absolutely hate when people try to cram everything into a genre (I like post-apocalyptic urban fantasy! And being a predictable consumer!), and seemingly that's the only general way to answer that question.

The problem is that it's a bad question to ask. You don't read kinds of books. You read authors. So the correct question is "what authors do you like". That question I can answer. Or, you can ask what they're reading at present. Also a good question.

I don't think any interesting person likes genres in the abstract; they like specific authors. Sometimes that leads to genres, sometimes it doesn't. Of course, the follow-up tends to be "what do you like about them?" Or, "what are their books about?" Which can be damn hard questions. Good novels aren't easily summarized, and pithy descriptions of them tend to sound stupid. And most people probably don't know the authors you like, so it makes for a confusing conversation. Talking about books with random people is hard.

Trying to work backwards into a general set of rules about what makes a book a book you like is very difficult, and makes for a pretty personal conversation. Probably an interesting one with the right person.