In his review of National Treasure, Roger Ebert points out the similarity of the movie's plot to the book The Da Vinci Code. As a side note, he describes what he thought of the book:
It is inelegant, pedestrian writing in service of a plot that sets up cliff-hangers like clockwork, resolves them with improbable escapes and leads us breathlessly to a disappointing anticlimax. I should read a potboiler like The Da Vinci Code every once in a while, just to remind myself that life is too short to read books like The Da Vinci Code.
I only read about a page and a half of The Da Vinci Code, but that was pretty much the impression I'd formed. It pleased me to see it summed up so succinctly. It's also a sharper, more biting review than you usually see Ebert dish out to most movies, made harsher by its dismissive brevity.