If I wanted to see what Vietnam was really like I'd watch a documentary or read a book. Speaking of, the book Tiger Force, about a platoon in Vietnam that got way out of hand, is really good. Two writers from my local paper (The Toledo Blade) won the Pulitzer for investigative reporting for it.
Full Metal Jacket is amazing, as is any Kubrick movie. He's the greatest filmmaker of all time in my book, and 2001: A Space Odyssey is my favorite movie of all time.