I woudln't call Kellys Heros a war movie, just a crappy movie.
I thought Thin Blue Line was an excercise is making a bad movie. Just basically a confused peice of garbage, certainly not a a real war movie.
A lot of good movies listed though. How about "The Green Berets"?
Saving Private Ryan gotta be one of the top five in any list.
Then I like
12 O'clock High
The Longest Day
To Hell and Back
BlackHawk Down
Those 5 in my opinion both tell good stories and maybe reflect in a small way the story of men in battle and what they experienced.
Other notables that come to mind would include
A Bridge to Far
Platoon (story is a little bizarre)
Band of Brothers (more a great mini-series, but better than most war movies)
Thirty Seconds over Tokyo
The Bridge at Remagen
Patton (of course)
Battleground
Battle of Britain
The Big Red One
Too many to list.
dago