This might not fit in exactly with the movies that have been listed (all fiction, from what I could see), but I would put forward three of the lead characters in the movie We Were Soldiers. (This is the movie adaptation of the non-fiction book We Were Soldiers Once...And Young.)

Mel Gibson as Col. Hal Moore. Family man, student of military history, master tactician, he leads from the front.

Sam Elliott as Sgt. Maj. Plumley. Career soldier, tough as nails, he is Hal Moore's right hand man, and refuses to use the M-16, preferring to stick to his .45 automatic. As a side note, Sam Elliott plays an almost perfect Sgt. Maj. Plumley. "If any of you sons a b**ches call me 'grandpa...I'll kill you."

Greg Kinnear as Maj. Bruce "Snake" Crandall. I know, I know, I can hear some of you groaning from here. But seriously, this guy is a Huey pilot, he personally can't shoot back at anything, and yet he brings his helicopter into these ferocious firefights to drop off supplies and pick up the wounded, again and again, without question, without hesitation. Tell me that ain't a big set of stones!

But that's just my opinion, and I could be wrong.