My personal taste is not really with war movies, but with documentarie series. I can recommend:
The Apocalypse series from National Geographic, this covers ww1, ww2, Verdun, Stalin and Hitler each with a series of about 5 episodes.
Hitler’s Inner Circle is a series of which the name explains the plot. It’s 10 episodes (I think) about the people around Hitler (not Hitler himself though) between 1920 and 1945, and some even after 1945. It features both real footage and reenacted scenes.
The War and the Vietnam War by Ken Burns are my favourites, because they use interviews of veterans and people who stayed home during both wars and explain the entire war, from frontline to home front in detail.
WW2 in colour is a series which focuses on the 2nd world war and summarizes it in 13 or something episodes using coloured footage, great for the large picture of the war and military history.
For series about the Holocaust I recommend Auschwitz: the Nazis and the Final Solution by the BBC and Einsatzgruppen - les commandeurs du mort by a French director (forgot his name). Auschwitz focuses on the evolution of the Concentration camps, mainly Auschwitz and features re-enacted scenes, and Einzatsgruppen uses real footage and testimonies from SS members, eye witnesses and Holocaust survivors.
The final documentary series I would like to recommend is Hitler’s Bodyguard, which focuses on (you guessed it) Hitler’s bodyguards, but also his bunkers, his train and his planes.
All of these are on Netflix (at least in the Netherlands), so enjoy!