The Longest Day (1962)
Mostly True!
The Longest Day was, for a long time, the cinematic standard for D-Day, and one of the most important war movies of the last half of the 20th century.  Starring John Wayne and Robert Mitchum, the film tells the story from both the American and German perspective and to ensure accuracy, they had advisors from both Allied and Axis forces that were actually at D-Day and participated in the battle.
Beyond a few cinematic abbreviations needed in regards to film running time and condensing the story into a more easily digestible narrative, where The Longest Day starts to fall apart is the beach landings themselves.  In the film, the main characters are shown being sheltered by a concrete wall, and having the time to look around, consider their approach.  In real life, there was no shelter and the pace was relentless.  (The concrete wall will be replaced by a more accurate dirt berm in Saving Private Ryan years later.)  Also, the fillm simply isn't that bloody or violent, but this is more a convention of the culture of the era in which the film was produced.  Unfortunately, this likely gave an entire generation of filmgoers and unrealistic view of the savagery of the conflict.
Edge of Tomorrow (2014)
Mostly Accurate...At Least In Regards to the Frenetic Pace of Battle
This sci-fi film, tells the story of an alien attack on the planet and an amphibious invasion on the beaches of Normandy by U.S. and British forces to try and infiltrate the European continent where the aliens have taken hold. Â So in reference to the World War II D-Day assault, yeah, it's not really relevant.
However, the film does get one thing amazingly right.
 Which is that the scene of battle on the beach, are the most realistic, intense, and disorienting, that I have ever seen in a battle film.  The first time Tom Cruise's character drops onto the beach to fight (he ends up doing this a lot, as he's stuck in a time loop, so he repeatedly fights the same battle) he is so scared that he is shaking.  The screen is so filled with action occurring all around him, that Cruise can barely get his bearings.  Death and soldiers dying all around him is a sort of perpetual constant.  It's dizzying and overwhelming.
Which, is how I imagine, the real D-Day was. Â And for this reason alone, i count the film as "Mostly Accurate"...with some caveats.
The Big Red One (1980)
Too Small in Scope!
Unfortunately, it's difficult to assess The Big Red One for historical accuracy because it's re-creation of D-Day is simply too small in scope. Â The film had a pretty small budget, even for its time period, and consequently, we're treated to what is essentially looks like a single platoon trying to take the beach. Â In reality, the invasion occurred over many beaches simultaneously and involved tens of thousands of soldiers.
 The Big Red One would have you think it was thirty guys.  The differential comparison in scope from the film to real life is almost laughable, making any sort of historical analysis almost a mute point.
We'll have to pass on this film.
Mostly Accurate!
This 2004 TV movie focuses more on Eisenhower and the political machinations behind the scene rather than the battle, itself. Â That said, the film does a remarkable job detailing specific details that most other films would gloss over, to include: Â Separately naming the Canadian detachments that participated in the conflict (usually the Canadians are omitted, their participation just referred to as part of the "British effort"), and even accurately referencing a speech Eisenhower had prepared in his pocket in case the invasion failed.
 T, here are a few small errors in the film, including getting the name wrong of a Major, and reference to an amphibious landing vehicle that didn't exist until ten years after the conclusion of the war.  But mostly, this ambitious television movie gets it right.
Nails It!
Spielberg set out to create the definitive cinematic tail of D-Day, and he succeeds in this film, which made my best of World War II movies list (it also made my list for best battle scenes of all time.) Veterans of the D-Day invasion who saw the film sited it as being the most realistic re-telling they'd ever seen.
That's not to say the film doesn't have its historical detractors. Â There are those who point out that there are the wrong number of metal crosses on the beach, and that the German position in the film is too fortified, and that the soldiers were more "bunched together" in the film than they were in real life.
 But this is mostly nitpicking.  When you get to the point where you're discussing whether the soldiers were as bunched together as portrayed in the film, you know you've succeeded on the important stuff.
Most importantly, unlike with The Longest Day, Spielberg set out to show battle as being truly horrific and carnage filled, meaning this film's D-Day sequence provided one of the bloodiest scenes in war movie history.
Mostly True!
The Longest Day was, for a long time, the cinematic standard for D-Day, and one of the most important war movies of the last half of the 20th century.  Starring John Wayne and Robert Mitchum, the film tells the story from both the American and German perspective and to ensure accuracy, they had advisors from both Allied and Axis forces that were actually at D-Day and participated in the battle.
Beyond a few cinematic abbreviations needed in regards to film running time and condensing the story into a more easily digestible narrative, where The Longest Day starts to fall apart is the beach landings themselves.  In the film, the main characters are shown being sheltered by a concrete wall, and having the time to look around, consider their approach.  In real life, there was no shelter and the pace was relentless.  (The concrete wall will be replaced by a more accurate dirt berm in Saving Private Ryan years later.)  Also, the fillm simply isn't that bloody or violent, but this is more a convention of the culture of the era in which the film was produced.  Unfortunately, this likely gave an entire generation of filmgoers and unrealistic view of the savagery of the conflict.
Edge of Tomorrow (2014)
Mostly Accurate...At Least In Regards to the Frenetic Pace of Battle
This sci-fi film, tells the story of an alien attack on the planet and an amphibious invasion on the beaches of Normandy by U.S. and British forces to try and infiltrate the European continent where the aliens have taken hold. Â So in reference to the World War II D-Day assault, yeah, it's not really relevant.
However, the film does get one thing amazingly right.
 Which is that the scene of battle on the beach, are the most realistic, intense, and disorienting, that I have ever seen in a battle film.  The first time Tom Cruise's character drops onto the beach to fight (he ends up doing this a lot, as he's stuck in a time loop, so he repeatedly fights the same battle) he is so scared that he is shaking.  The screen is so filled with action occurring all around him, that Cruise can barely get his bearings.  Death and soldiers dying all around him is a sort of perpetual constant.  It's dizzying and overwhelming.
Which, is how I imagine, the real D-Day was. Â And for this reason alone, i count the film as "Mostly Accurate"...with some caveats.
The Big Red One (1980)
Too Small in Scope!
Unfortunately, it's difficult to assess The Big Red One for historical accuracy because it's re-creation of D-Day is simply too small in scope. Â The film had a pretty small budget, even for its time period, and consequently, we're treated to what is essentially looks like a single platoon trying to take the beach. Â In reality, the invasion occurred over many beaches simultaneously and involved tens of thousands of soldiers.
 The Big Red One would have you think it was thirty guys.  The differential comparison in scope from the film to real life is almost laughable, making any sort of historical analysis almost a mute point.
We'll have to pass on this film.
Mostly Accurate!
This 2004 TV movie focuses more on Eisenhower and the political machinations behind the scene rather than the battle, itself. Â That said, the film does a remarkable job detailing specific details that most other films would gloss over, to include: Â Separately naming the Canadian detachments that participated in the conflict (usually the Canadians are omitted, their participation just referred to as part of the "British effort"), and even accurately referencing a speech Eisenhower had prepared in his pocket in case the invasion failed.
 T, here are a few small errors in the film, including getting the name wrong of a Major, and reference to an amphibious landing vehicle that didn't exist until ten years after the conclusion of the war.  But mostly, this ambitious television movie gets it right.
Nails It!
Spielberg set out to create the definitive cinematic tail of D-Day, and he succeeds in this film, which made my best of World War II movies list (it also made my list for best battle scenes of all time.) Veterans of the D-Day invasion who saw the film sited it as being the most realistic re-telling they'd ever seen.
That's not to say the film doesn't have its historical detractors. Â There are those who point out that there are the wrong number of metal crosses on the beach, and that the German position in the film is too fortified, and that the soldiers were more "bunched together" in the film than they were in real life.
 But this is mostly nitpicking.  When you get to the point where you're discussing whether the soldiers were as bunched together as portrayed in the film, you know you've succeeded on the important stuff.
Most importantly, unlike with The Longest Day, Spielberg set out to show battle as being truly horrific and carnage filled, meaning this film's D-Day sequence provided one of the bloodiest scenes in war movie history.