I liked "Tora Tora Tora" for a wwII Pacific War film.
Regarding Vietnam, I was in High school, and watched it unfold each night on the news.
i read a number of books, later as an adult, some of which were made into movies, or documentaries.
VietNam a Television History" a history book... the companion to the 13 part TV miniseries.
"The 10,000 Day War" the companion book to a 8 part TV miniseries. I like that one much more... it was not as politically correct as the 13 part series, and spoke of the secret negotiations to end the war, and the funds promised to the North (that were beyond Nixon's authority to promise).
"The 13th valley" The story of a platoon, who humped the hills and valleys, take an area, only to relinquish it and take it again. The frustration of being a grunt, seeing your brothers get killed or maimed, and never seeing the enemy. When I watched the movie "Platoon" (which I also liked), I wondered if it was based on the 13th Valley. Certainly not, but the experiences were similar. If you like the movie Platoon, you'd likely enjoy the book the 13th Valley.
"Chickenhawk" huey helicopter pilot. They were heroes. It was planned to make it a movie, but wasn't.
Marine Sniper: Carlos Hathcock. There have been a number of sniper movies. None of them bad.
"The Flight of the Intruder" ...read the book, saw the film. I enjoyed them both.
"The Tunnels of Chu Chi" The Tunnel Rats. The book helps to understand how determined the enemy was to fight a gorella war. How they would crawl underground, pop up, and ambush a patrol, and disappear, frustrating our patrols.
More recently... "Black Hawk Down" They had GPS capability, but didn't bring it. If only they were as small and lightweight as our cell phones are today!