What do you like in a novel?

I like to read historical fiction books, most specifically books about the Renaissance period and books that take place during both early and Medieval Times. I am at the moment reading, World Without End, the sequel to the book, Pillars of the Earth. I like a little bit of everything in a book, not necessarily all at once, but I don't mind reading a book written through different themes, as long as its done good and not to overly dramatic. But, every reader is different, and what may be favorable for one person may not appeal to a different reader.