I think most people find they prefer certain reading genres.
Mine have changed over time. When I first began to read for pleasure (high school, but few books) I preferred fiction. As an adult, once I really began to read more, I found I enjoyed mostly non fiction selections. Many of those books were related to my Christianity or marriage/family. Now that I read even more, I have found that I enjoy both fiction and non fiction.
These days I can really appreciate the creativity required to produce a riveting and well written fictional story. I think that preference has been influenced by my homeschooling our kids. Together we have truly enjoyed some wonderful books! My avoidance of books as a pre-adolescent means I have a lot of uncovered ground in juvenile fiction!
In regard to fiction I've branched into some areas I previously hadn't ventured. Around the time we moved to England I found Jasper Fforde's books and really fell for them; they are so smart but very funny.
I enjoy biographies, often those written about film or tv stars of the 1940s-1960s.
I really like to read memoirs. A true story is sometimes the best!
I occasionally like a mystery.
I enjoy well written juvenile fiction.
I am learning that I have a real affinity for classic British literature too!