The Da Vinci Code
All in all, it was actually watchable. Sure, the abysmal acting or the lack of any acting whatsoever was a real turnoff for me, but the vat of popcorn and absolutely insane ahistorical conspiracy theories got me. Even though the actors had been hired just to stand there and look preofessional, I had to see how the thing ends, even if I guessed the plot, or who the main players were, from the get-go. Sure, the betrayal took me by surprise by I merely shrugged if off because the focus of the movie was somewhere entirely else than story progression and character chemistry. And the art and sights almost gave the movie one star out of seven.
Then again, I haven't read the book and didn't pay anything to see the movie. Did it affect my experience? Beats me.