Wasn't Coming Home a movie about a soldier returning home? I think it starred Jon Voight and Jane Fonda. What about Born on the Fourth of July I know that was about a Vietnam vet. Was The Deerslayer about a soldier? I'm sure there are plenty out there. Aside from these, I'm not sure, but eh above posters are very reliable, so there should be some good information there.
I wish I could remember the name of the one-act play I directed 20 years ago about a returning soldier, but I'm just drawing a blank. A quick search didn't help me, but I did see several one-acts which do contain some kind of soldier/war theme. I'm not sure how applicable or appropriate it is, but I've heard great things about A Soldier's Play by Charles Fuller (I think). Explores some pretty heavy issues, so it may not be what you're looking for, but I'm confident you'll find something you can use out there.
What about A Few Good Men? Although the Tom Cruise movie is what likely made the title so popular, my husband was in a college production of the stage version and loved it. In fact, in everything he did, it was his favorite. It seemed to be well received by both students and audiences alike.
The first series of plays that comes to mind with a military theme is David Rabe's famed Vietnam trilogy written during the turbulent 'Seventies: The Basic Training of Pavlo Hummel (1971), Sticks and Bones (1971), and Streamers (1976). I first read all three of them in a college theatre class shortly after the final installment, and was fortunate enough to see a professional production of Streamers soon after. These plays were among Rabe's earliest efforts, and they helped to build his reputation as one of America's finest playwrights. Rabe also wrote The Orphan (1973), another play based on a soldier's war experiences.