Books are meant to be read   Mm.  Well, I suppose I was making an unconscious division that textbooks are not "books".  Another serious question, possibly stemming from not being awake enough yet:  what kind of non-fiction (barring textbooks, manuals, etc.) doesn't have a story line?  I've read all the biographies of Rupert Brooke that I could get my hands on, including one that was just letters to and from him.  I loved reading the "story" about how his life and his relationships developed; many of his friends fell in love with him, and I did too.  History books certainly have a story line.
Back to fiction:  one of my dearest friends absolutely loves novels.  We've tried exchanging books a couple of times, but our tastes just don't fit.  I lent her my first Laurie King--she was unimpressed.  She lent me one of her favorites, about a young boy who is longtime pen pals with someone who turns out to be a girl; they marry, of course.  I was bored nearly to death, but nothing like I was when she and her sister made me read Secrets of the Ya-ya Sisterhood.  [shudder]  As to mysteries, I have discovered that prolific writers tend to be a bit formulaic*, which, I suppose, is understandable--I don't see how anybody can write thirty mystery novels and have each one completely different.  But I will say for Dick Francis, I love his main characters, and that I have consciously adopted a lot of their characteristics for myself.  
*It was interesting to see how his obligatory sex scenes changed as society's permissiveness changed.