Dan Brown's The Da Vinci Code is not just bad in content, as biblical scholar and theologian Craig Blomberg shows here, but it's badly written as well, according to linguist Geoff Pullum. Of course, Blomberg, who recognizes its awful content, found it a good read, so something else must count as a good-making feature of a novel, even if its content and style are both bad.
Update: Now I don't know what to think. My brother Rick knows good literature if anyone does, and he says the following:
I read a bit of the book Angels & Demons yesterday. This is the book that
precedes The Da Vinci Code. It isn't hardly as disturbing as people keep saying. And it's much better written than the reviews of Da Vinci code have been saying.
But it is a somewhat different topic (though same main character.) It's a political thriller involving both the issue of science vs. religion and the Illuminati. And a conspiracy plot to blow up the Vatican City during a
papal conclave just after a pope died, in an effort to stamp out the church
entirely. It's interesting, moves right along, and is hard to put down. I have no idea how the 2nd book rates yet.
and then in a later email:
This book Angels & Demons is very interesting. It's a political thriller,
mostly about the chase. But it has some interesting details about art,
architecture, religious fights, science, and more.