The problem with Vietnam movies is that the war was (and is, even now) such a divisive topic; certainly abroad, but especially in America. Very few movies, even now, seem willing to look at it without layers of nuance and "meaning" on top. Films like Apocalypse Now and FMJ are brilliant on their own terms, but as movies *about* war they fall somewhat short for me. They don't communicate an impression of what the soldiers who fought the war went through, except in abstract and metaphorical ways. Maybe you like your war films that way. I don't. I'd rather see things depicted with some sort of accuracy for once.
Any of us can name a half-dozen "soldier" films about WWII (Big Red One, Saving Private Ryan, A Bridge Too Far, 12 O'clock High, and so on). How many can you name dealing with 'Nam?
Hamburger Hill, We Were Soldiers... maybe Bat 21 and Tigerland. That's about it for me. And in my opinion, the one that did the best job was We Were Soldiers.