Eric Bogle is hard to beat, and gets my vote ... Band Played Waltzing Matilda and No Mans Land, both great.

A very moving anti-war song was written 1995 by Margaret Nelson:

"Died in the War"

She's middle-aged now. She uses her time
For her friends and her work and improving her mind.
She's lonesome tonight. She knows who it's for:
Her sweetheart, who died in the war.

When her lover came home, she thought that her life
Would be husband and babies, mother and wife,
But the man was a stranger who walked through her door.
Her sweetheart had died in the war.

(Bridge tune): Died of the bullets, the mines and the shells,
Died with his buddies in two years of hell
With a wall round his heart where love needs a door.
Her sweet heart he died in the war.

He's a pretty good boss. he works with his crew
Taking old buildings and making 'em new.
Some nights he drinks less. Some nights he drinks more.
His sweetheart, she died in the war.

(Bridge tune again) Died of the hard words, the booze and the pain,
Died of the distance, he couldn't explain.
The girl was a stranger who walked out the door
His sweetheart, she died in the war.

She's middle-aged now. She uses her time
For her friends and her work and improving her mind.
She might have done less. She might have had more.
Her sweetheart he died in the war.

Copyright 1995 by Margaret J. Nelson