What I find so strange about The Imitation Game that all of this is pretty well-known; anyone who has skimmed the Wikipedia article of Turing and the overview article on breaking Enigma knows that the movie is pretty much complete horseshit. Most of the alterations in the movie removed things that would have made the movie more interesting instead of the utterly bland story they made up.
I'm struggling to think of any movies that are really historically accurate - the point is to tell a good story to get people to watch it to make a profit.
Edit: I'm Scottish so Braveheart is the obvious example - entertaining movie but wildly inaccurate and even manages to get who/what the term "braveheart" refers to wrong.
Gettysburg and its prequel (Gods and Generals). The dialogue and character motivations may or may not be accurate, but the battles it depicts are pretty accurate.
