CLASH OF THE TITANS
The title implies that in this movie there is a battle between titans.
– Which implies that there is a multitude of titans in this movie.
– Which implies that there is at least one titan in this movie to begin with.
– Which there is not.
Remember the Titans was a more accurately titled movie. At least they realized they were missing something.
Benjamin T. Collier's Blog 
Of course, this is just a nomination. If anybody has another example of an inaccurately titled movie then throw it in for consideration. : )
I would also like to nominate The Warriors.
They spent the entire movie trying NOT to get into fights.