Lot's of great war movie ideas on this thread. In particular I'm going to have to check out 'Downfall'.
Regarding my favourite war movies on dvd the ones that are the best, IMHO, perfectly combine and balance story, acting, action, effects along with a stellar print and sound.
Using this criteria my hands-down favourite has to be:
Apocalypse Now REDUX - a mesmerizing film that is a longer than the original and the additional scenes work well and expands Martin Sheen's character so that he becomes more identifiable and likeable.
Enemy at the Gates - understated cat and mouse war drama.
Das Boot - I don't have it on Superbit yet but given the big sale on right now at Futureshop and positive comments I think I will.
Lawrence of Arabia - I actually just bought this on Superbit last night and it looks great. I do notice minor pulsing variations in the light level but clarity, colour and detail is very nice.
Full Metal Jacket - Kubrick takes you to the Vietnam battlefield and leaves you there.
Schindler's List - Not the same kind of war movie as the others but still an important film and my choice over Saving Private Ryan anyday.
Other historical conflicts:
Ben-Hur - nice picture quality, great movie
Braveheart - down right gritty and stirring
Gladiator - the starting battlescene vs the Germanic barbarians is so strikingly modern that you almost don't notice they are using only bows, arrows and catapults