I like the films that either:
Follow true events (sort of)
The Dam Busters
A Bridge To Far
The Longest Day
Battle Of The River Plate
Shindler's List
The Great Escape
Black Hawk Down
Tora, Tora, Tora
The Battle Of Britain
Or show war as true horror
Platoon
Full Metal Jacket
Saving Private Ryan
Casualties Of War
Apocalypse Now
Das Boot
The Cruel Sea
Ice Cold In Alex
Bridge On The River Kwai
All Quiet On The Western Front