Some great WWI movies that I know are released on DvD. Besides The Lost Battalion, here are a few for you to ponder about--all if which are geat on their own accounts:

Both versions of: All's Quiet on the Western Front.

Biggles, Sergeant York, The Fighting 69th, Hell's Angels, Dawn Patrol and I think Lafayette Escadrille was released but not 100% sure?

A few i'd love to see released:

Anzacs: The War Down Under w/ Paul Hogan. This one has the usage of tanks.

The Lighthorsemen - Usage of Australian Cavalry.

I thought that Gallipoli sucked prune pits, as well as Breaker Morant.

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Lost are only those, who abandon themselves) Hans-Ulrich Rudel.