The Green Berets is just about the only "appropriate" movie on Vietnam that I
can show and not get into serious trouble for content, meaning that forbidden "R" rating. It's a propaganda piece and just about the only pro-Nam film ever made. But it is fairly realistic as to the role of SF in 'Nam. I guarantee you that every time an SF operator hears the song, it brings tears to their eyes, especially these days. Most of my own buddies in the SF have told me that they got into the outfit because of THAT movie and none other.
The Devil's Brigade might have been made because of The Dirty Dozen but it is pretty historically accurate as well, right down to the final assault on the mountain in Italy. They were made up of misfits from Americans and crack Canadian troops; and yeah there was a lot of Hollywood (like the training and brawling) but a lot was fairly accurate, too. The First Special Service Force never retreated and never lost a battle, but they took heavy casualties and were disbanded before the end of the war due to attrition.
I knew a man who was in Darby's Rangers in Sicily and Italy. He was one of the few who escaped the encirclement at Anzio. He was then assigned to the First Special Service Force and from there became part of the 474th. When the war ended they were doing mop up operations in Germany but suddenly sent up to Norway to head off the Russians who were coming in over the top from Finland - it came very close to a real battle.
The man did not like to talk about the war much but I talked to him a little here and there about it for years. He died before I could get him to really open up.