I've just finished reading The Da Vinci Code. At last.
You'd expect better from a book that's been receiving so much publication.
The story has a brilliant plot - every aspect of a fantastic thriller/mystery is present. It's a great read, just like any other mystery story. Its only claim to fame is all the lovely theories on Mary Magdalene, that disembodied hand, Leonardo Da Vinci etc. New ideas. Apart from that, the story was a great read, but pretty much like any other good mystery.
You'd expect a lot more from a story that's probably given Dan Brown enough money to rival, uh, one third of J.K. Rowling's fortune.
Then again, maybe I just can't appreciate the true history of Christianity, seeing as I don't believe in God. And the holy grail isn't a solid object... I like that idea. But it could be portrayed a lot better. The book was dedicated to the union of the blade and the chalice. Interesting but a genius like Dan Brown could probably express it better...