1977 film by Sam Peckinpah about the Eastern Front from the perspective of the German Army. Amazing film. Has James Coburn as a cynical vet that's won the Iron Cross and ends up under the command of a Prussian aristocrat looking to win himself the Iron Cross. Really it's the kind of story you've seen told about the British Army a million times. Posh guy gets command because of his status but doesn't know anything about war and sees it as a route to glory. Gets forced to deal with the reality by a guy that knows how horrific a real battle is.
Except it's from the perspective of Germans and it's a Peckinpah film, so there are more layers and lots of insanity.
I've not watched a huge amount of war films but there are some good stories told about different sides of the war. Stalingrad, Days of Glory and Sophie Scholl - The Final Days are all worth watching. If you've not already, of course.