I think my main favorites are well written mainstream literary fiction, like Pulitzer Prize winners; horror, though I can't seem to find any I like other than Stephen King; I like young adult, supernatural and mainstream; some chick lit; ghost stories, which I think of as their own category, separate from supernatural and horror; and a few thriller/mystery types. I don't usually like high fantasy or books in which a child dies or is lost.
The thing about this-- there are exceptions to all of these. I like C. S. Lewis, a Christian writer. I like Jane Austen-- romance if there ever were romance.
Anyway, I finished the latest Stephen King book, and I'm scouring listmania tonight on Amazon. It's weird to feel like I've read everything in my favorite genres, when I KNOW that's not even close to kinda sorta possible.