6. "The 40 Year-Old Virgin" - The 40-Year-Old Virgin (2005)
Judd Apatow's first feature film is still arguably his best, though Universal obviously didn't think it was worth much time or effort when they first released it - not enough to check the spelling, anyway. Not quite an error that made its way into the movie itself (but an interesting addition to this list nonetheless), the words "40-Year-Old Virgin" require not one, but two hyphens, though nearly all of the original posters had the phrase written as "
The 40 Year-Old Virgin," which hilariously implies that the movie is, in fact, about 40 separate one-year old virgins (we still think that needs to be made). Universal eventually realised that they'd messed things up and - in subsequent poster releases - fixed the error, much to the admiration of grammar nerds the world over.