The LA Times posted a blog entry asking about the Top 10 Historically Inaccurate Films. To illustrate the concept, they used a picture from Apocalypto. Here's how I responded:
I review Native American-themed movies on my website. Here's a top 10 for this subcategory alone. Some of them are probably bad enough to compete with any historically inaccurate film.
They Died With Their Boots On
The Education of Little Tree [book and movie]
The Road to El Dorado
The Emperor's New Groove
Bury My Heart at Wounded Knee [TV]
Comanche Moon [TV]
Of course, any Western that depicts Indians as mindless savages, whooping and killing like animals, is bad. But this is only one mistake--albeit a big one. I don't know how it compares to movies with dozens of historical mistakes.
Addendum: The most inaccurate film in history may be an early screed such as The Birth of a Nation. A Technicolor spectacle such as Cleopatra. A "science-based" thriller such as 1 Million Years B.C. Or a revisionist exposé such as JFK. Any other nominations?
Of course, we're implicitly limiting ourselves to major motion pictures. If we got into B-movies about Hercules or Tarzan, Godzilla or little green aliens, I'm sure we could find thousands of horribly inaccurate films.