Jar Head does, in my opinion, present a good enough and gritty enough military drama to take a spot near Platoon and Apocalypse Now. While not quite up to the standards of Apocalypse Now, I rate it about on a par with Platoon.
Starring the brilliant Jake Gyllenhaal, it follows his journey through boot camp, and then into Saudi Arabia as the Gulf War breaks out, until the war ends. There isn't as much gore as you might expect, but that's not necessarily a bad thing.
Jake plays Anthony Swofford, who enlists in the Marines in the late '80s, and makes it through training, to be flown into Saudi Arabia just after the Gulf War breaks out. There follows a story of boredom, preparation, waiting and more boredom, before Anthony's unit finally gets to move out toward the enemy. I won't spoil the biggest surprise for you.
It's somehow a more personal story than Platoon - probably helped by the fact that it's based on a true story - and not quite as crazy as the latter part of Apocalypse Now. However, given what's gone before film-wise, I feel I can't quite justify giving this 5/5 (which is what I rate Apocalypse Now at) so it's going to have to be 4/5.