Shakespeare In Love
Shakespeare in Love won 7 Academy Awards and had a total of 13 nominations, so we can't deny it's a good movie. However, if we look at it from a historical point of view, it is quite the opposite.
The plot is basically about Shakespeare and his muse, Viola Lesseps, who helps him get inspired as he struggles to write Romeo and Juliet. The truth is that Viola never existed and Shakespeare didn't struggle at all while writing his masterpiece.
Amadeus
The 1984 movie Amadeus revolved around the life and death of Mozart, and the very first scene features an old Antonio Salieri, Mozart's supposed rival, confessing to poisoning and killing him.
While there have been many rumors that Mozart and Salieri were enemies, there's no evidence to back this up. They were more likely respectful colleagues, and Salieri was reportedly very distraught upon Mozart's death.
Braveheart
Braveheart was a huge success, but it wasn't really an accurate representation of the life of William Wallace and his fight for Scottish independence. For example, Isabella of France is portrayed as his love interest.
In reality, Isabella and Wallace never even met. When the events of the movie were going on, Isabella was only seven years old. Also, Wallace was a lesser noble and not a humble farmer as he is shown in the film.