I just finished reading the Illustrated version of the Da Vinci Code
and it is a real treat to have pictures of the paintings and places that are mentioned in the book. (the story does draw a lot on the Holy Blood Holy Grail theories) I think even of the Characters is called Sauniere
in both books. It is a fun read, although its written a bit like screenplay. As if you expect it to be made into a movie (which I think they are doing)