What is the best movie about Vietnam?

Combat Shock comes a close second.

Best is Apocalypse Now. Special mention to Full Metal Jacket and Platoon. Woo's A Bullet in the Head, whilst not about Vietnam per se, is excellent.

The Little Girl of Hanoi
Capsule by Jonathan Rosenbaum
From the Chicago Reader

Perhaps the most amazing thing about Hai Ninh's 1974 Vietnamese propaganda feature, partly filmed during the U.S. bombing of Hanoi in 1972, is how strong and accomplished and beautiful it is, given the almost impossible circumstances under which it was made. The simple but powerful story centers on a little girl wandering through the rubble of the city looking for her parents, until a soldier takes her under his wing. Told partially through flashbacks and incorporating everything from animation to documentary footage to studio rear projection, the film is remarkable not only for its sincerity and emotional directness but for its accomplished visual style. And though it was clearly designed to boost morale, its anti-American feeling is remarkably mild given what we were doing to Vietnam at the time, especially compared to the anti-Vietnamese sentiments expressed in The Green Berets and The Deer Hunter; there's even a sympathetic American character, a nurse shown caring for wounded Vietnamese.

I can't stand most American "Vietnam films"--they either abstract the conflict entirely (Apocalypse Now, which I recognize is a very impressive film but not one I care for) or take the stance that the war was notable for the "loss of innocence" experienced by US soldiers (The Deer Hunter, not a bad film either but one I never wish to see again in my life). Platoon was notable for illustrating America's victimization of the Vietnamese more than previous films, but the bulk of the film just appropriates the worst of the previous two categories. Also it's embarrassingly schematic. Oliver Stone's later pictures are better "Oliver Stone pictures" if that's what you want. NB: I haven't seen Heaven and Earth.

I didn't find Combat Shock boring. Yeah, it's a cheap piece of crap. But it's an ambitious cheap piece of crap.

Bat 21 and Hamburger Hill are both decent movies.

Birdy is another good movie that has Vietnam weaved in it's story. The ending is one of my favorites. The book that Alan Parker based the movie upon was set in WWII and was also made into the movie A Midnight Clear.

I really liked Platoon when I first saw it, but after hearing my vet uncle's rant about hating that movie, it makes me feel weird. I suppose Stone should have just made a movie directly about Calley. The big jesus on the cross ending of Platoon is a bit much. Not that Apocalypse Now or Full Metal Jacket don't come off a bit overblown, but they come off with much more gusto. Either way, Born on the Fourth of July is a better movie anyway, at least to my way of thinking.

The movie that probably best sums up the insanity of that conflict is The Killing Fields or even better Vietnam: A Television History. Vietnam: A Television History is a documentary that will wring your guts out.