Spartacus
Tora Tora Tora
Midway
Stalag 17
The Dirty Dozen
The Bridge Over the River Kwai
The Caine Mutiny
Patton
The Great Escape
Saving Private Ryan

In no particular order:
Saving Private Ryan
Full Metal Jacket
Platoon
Apocalypse Now
The Longest Day
Dr. Strangelove
Lawrence of Arabia
The Bridge on the River Kwai
The Deer Hunter
The Hurt Locker
Schrodinger's cat walks into a bar and doesn't.

1 Platoon
2 Schindler's List
3 The Deer Hunter
4 Saving Private Ryan
5 Full Metal Jacket
6 Apocalypse Now
7 Hacksaw Ridge
8 Born On the Fourth of July
9 American Sniper
10 Inglorious Bastards

In a very particular order, from top rated down:

1. Apocalypse Now
2. Black Hawk Down
3. The Longest Day
4. A Bridge Too Far
5. Gettysburg
6. Glory
7. Platoon
8. Paths of Glory
9. Northwest Passage
10. The Siege of Firebase Gloria
    I've lived upon the edge of chance for 20 years or more
    Del Rio's Song

My top 3 ones are
Inglourious Basterds
Full Metal Jacket
9th Company (9 rota)

Ok I'm gonna stretch definitions: Band of Brothers.
Best ever.

1- Kelly's Heroes
2- The Big Red One
3- Full Metal Jacket
4- Midway
5- The Hunt for Red October
6- The Dirty Dozen
7- The Great Escape
8- Red Dawn
9- Heartbreak Ridge
10-Hamburger Hill
I'd include The Good, The Bad & The Ugly, Dances with Wolves, Duck, you Sucker & Good Morning Vietnam if they had more parts of the wars shown that they took place during.

'War' is far too wide a genre to only pick 10.
But in terms of films that literally show war-

1. Apocalypse Now
2. Ran
3. Saving Private Ryan
4. The Deer Hunter
5. Lawrence of Arabia
6. Atonement
7. Das Boot
8. Intolerance
9. Paths of Glory
10. All Quiet on the Western Front
    Lots of incredible films within broader genre of war:
    Grave of the Fireflies
    Schindler's List
    The Best Years of Our Lives
    etc.

full metal jacket
apocalypse now
hurt locker
saving private ryan
come and see
deer hunter
the last samurai
enemy at the gates
pan's labyrinth
letters from iwo jima

1. Saving Private Ryan
2. Lone Survivor
3. Black Hawk Down
4. Schindler's List
5. Letters from Iwo Jima
6. Fury
7. American Sniper
8. Kelly's Heroes
9. Full Metal Jacket
10. Apocalypse Now

Wow, just 10? That's tough!
My list would probably have to go

1. Full Metal Jacket
2. Apocalypse Now
3. Patton
4. American Sniper
5. Dr. Strangelove, or: How I Learned To Stop Worrying and love the Bomb!
6. Schindler's List
7. Kelly's Heroes
8. Platoon
9. Saving Private Ryan
10. Braveheart
    Honorable Mentions (and my sincerest apologies to): Barry Lyndon, Paths of Glory, Lone Survivor, All Quiet on the Western Front, Black Hawk Down, The Dirty Dozen, Lawrence of Arabia, The Thin Red Line & The Hunt for Red October.

Based on my rankings in "My Favorite Films" list.

1. Three Kings
2. The Hurt Locker
3. Apocalypse Now
4. Full Metal Jacket
5. Platoon
6. Hamburger Hill
7. Dr. Strangelove
8. The Last Samurai
9. Paths of Glory
10. Valkyrie
    Signature.

Saving Private Ryan
Platoon
Apocalypse Now
The Deer Hunter
First Blood
Black Hawk Down
The Dirty Dozen
When We were Soldiers
The Steel Helmet
The Hurt Locker
Fury
www.thecultofhorror.blogspot.com

Some excellent lists. Nearly all of mine are covered but I would be tempted to add Born on the Fourth of July and maybe Casualties of War

1. Apocalypse Now
2. The Thin Red Line
3. Full Metal Jacket
4. A Field In England
5. Platoon
6. Saving Private Ryan
7. Downfall
8. A Bridge Too Far
9. Paths of Glory
10. Windtalkers

The Great Dictator
Dr. Strangelove
Paths of Glory
The General
The Wind Rises
The Bridge on the River Kwai
Saving Private Ryan
Full Metal Jacket

Thank you! I hardly ever hear Hamburger Hill get a mention, but it's such an amazing film!
Signature.

In no order
1.Platoon
2.The Deer Hunter
3.Full Metal Jacket
4.Saving Private Ryan
5.Apocalypse Now
6.Patton
7.Jarhead
8.We Were Soldiers
9.Hamburger Hill
10.The Bridge on the River Kwai

Ranked in order, i'm not counting movies that are set in war time but don't have combat or at least it's not the main focus, movies like Schindler's List and The Pianist

1. Full Metal Jacket
2. Letters From Iwo Jima
3. Saving Private Ryan
4. Zulu (1964)
5. Platoon
6. Das Boot
7. Ji Jie Hao (2007)
8. We Were Soldiers
9. Lone Survivor
   10 Black Hawk Down

My top favorite war films can be seen here:
http://www.imdb.com/list/ls059870062/
.

Saving Private Ryan
Platoon
Apocalypse Now
A Bridge Too Far
Paths of Glory
Windtalkers
Kelly's Heroes
Pretty Village, Pretty Flame

Apocalypse Now
Ran
Lawrence of Arabia
The Seven Samurai
Gladiator
Paths of Glory
Platoon
Patton
The Caine Mutiny
The Bridge on the River Kwai
Almost made the cut;
Kagemusha
BB
it is just in my opinion - imo -

I am young, so as a result I have not seen as many movies in my time as a lot of people here. But I can safely say that The Thin Red Line is, in my opinion, one of the worst that I have ever seen

I really think such a list should be more specific, such as in time frames.
War movies before firearms, WWI, WWII, Vietnam, etc
But in general:
Full Metal Jacket
Saving Private Ryan
Inglorious Bastards
Lone Survivor
Black Hawk Down
Gettysburg
The Thin Red Line
Kingdom of Heaven
Braveheart
The Last Samurai
In no specific order. There are so many good ones, though.