What film best captures what being in the military is truly like?

The movie that most closely resembles my experience in the military would be full metal jacket, that covers boot camp to a tee. As far as the the remaining time in service it's a toss up between stripes and MASH.

The Boys From Company C. Perhaps the most accurate depiction from the Vietnam Era.

There are a lot of great ones and some not so much. As a Navy destroyer veteran I'll have to say The Enemy Below and The Caine Mutiny. Makes me feel almost like I'm back onboard ship!

No one has mention the movie “ Green Berets” . Yea it was a little long in the tooth with John Wayne being John Wayne, but that extraction scene of the General by the MC-130 Fulton extraction System was pretty cool. The Green Berets were a bit of a mystery during the war but this movie put them out there.
Then there’s was that song by Barry Saddler “Ballad of the Green Berets”

Ironically, though full of Hyperbole and exaggeration. MASH had a realistic feel with the dimensions of the various characters.

Full Metal Jacket, in my opinion, gives the most accurate depiction of basic training I’ve ever seen in a Hollywood movie. When civilians ask me what boot camp was like, I always recommend they watch that movie to get a feel for the experience.

As far as life as an infantryman, on the line, I think Platoon is the most accurate portrayal of life as a grunt. The hardships, the misery, the exhaustion, and the brutality - are all depicted very accurately in this film. Oliver Stone (a former infantryman and Purple Heart recipient) did a fantastic job giving the viewer a real taste of life as a combat infantryman in this movie.

A tv show called Over There, they Took actual Soldiers Stories and made it into a Series only ran for 1 season

I could name a few that aren't even close to accurate.

I agree about Taking Chance... damn good movie

Generation Kill does a pretty good job at points.