I have a list from best to worst:
Band Of Brothers
Battle Of The Bulge
A Bridge Too Far
Von Ryan's Express
Kelly's Heros
When you say it's a subject you know nothing about, do you mean the Holocaust? Obviously, there are many, many books on the subject. I'm sure we could make a recommendation or two if you're interested.
Here's a list of popular movies over the years, to jog your memory:
The Green Berets
The Hunt for Red October
Saving Private Ryan
The Duelists
Gallipoli
Alexander
Henry the V
A Bridge Too Far
Platoon
Downfall
The Thin Red Line
Red Badge of Courage (1951)
Cross of Iron
Zulu
The Man Who Would Be King
Paths of Glory
Big Red One
El Cid
Kelly's Heroes
Battleground
Stalag 17
A Midnight Clear
Tora Tora Tora
Blackhawk Down
The Wind and the Lion
Glory
The Dambusters
633 Squadron
The Heroes of Telemark
Full Metal Jacket
The Longest Day
The Great Escape
None But the Brave
Band of Brothers
Twelve O'clock High
Shenandoah
The War Lord
Waterloo
The Grand Illusion
Gettysburg
The Beast
Ran
Kagemusha
Das Boot
Apocalypse Now
Lawrence of Arabia
Dances with Wolves
In Harm's Way
Ice Station Zebra
The Sand Pebbles
Thirty Seconds Over Tokyo
The Bridges at Toko-Ri
Men of the Fighting Lady
Fail-Safe
Patton
Son of the Morning Star
Heaven and Earth
The Wild Geese
The Patriot
Lord of the Rings trilogy
Braveheart
The Secret of Santa Vittoria
Sea of Sand
The Cruel Sea
Battle of Britain
Breaker Morant
The Life & Death of Colonel Blimp
All Quiet on the Western Front (1930)
Soldier of Orange
The Small Back Room
Barry Lyndon
April Morning
Shogun
Northwest Passage
Up Periscope
Torpedo Run
War and Peace/Voyna i Mir
Utu
The Light Horsemen
The Winter War
Sgt. York
The Blue Max
Stalingrad
Decision Before Dawn
The Bridge
Pork Chop Hill
The Vikings
Rough Riders
Guns of Navarone
**** the Defiant
The Horse Soldiers
All the King's Men
Alamo
Doctor Strangelove
The Dirty Dozen
Battle of the Bulge
300 Spartans
Alexander the Great (Richard Burton)
Final Option/Who Dares Wins
Dogs of War
Khartoum
Kingdom of Heaven
Sink the Bismarck
The Grand Fleet
Port Arthur
Battle of the Japan Sea
The Last Samurai
Seven Samurai
Zulu Dawn
Hellcats of the Navy
Enemy at the Gates
Alexander Nevsky
The Alamo (John Wayne)
The Enemy Below
They Were Expendable
To Hell and Back
Sahara (1943)
Sands of Iwo Jima
84 Charlie Mopic
Master and Commander
Bataan
Red Dawn
The Dawn Patrol
The Caine Mutiny
Red Badge of Courage (1974)
Jarhead