It would be nice to include the servicemen (& women) of all countries, as well as the veterans. Of course, if someone does not wish to include their info for any reason, that's OK to.
NOTE: The next few paragraphs are for those considering joining the US Military. However, seek out a wide variety of sources and opinions before deciding to join/not join...
My background is mostly Air Force (flying, engineering, management), though I do have some special Army training too. No, I'm not a recruiter. As someone who supervised and counseled a lot of 19, 20, 21 year olds coming in to my units right out of tech school, my input to those considering joining an all-volunteer force is to enlist because you really
want to... not on an impulse. Do your research about what branch of service, and what job suits you best.
In today's Military, you will likely not be guaranteed the exact job you desire before signing up (
get it in writing, never take a recruiter's word for it, LOL 
)... this is the
Military, not a civilian job. However, if you are really uptight about doing a specific job... there may be a way: join the Reserves or National Guard. That local unit can often be flexible and tell you exactly how they plan to use you before you commit. If you go Active Duty, and the needs of the nation change, you can be re-assigned to any number of jobs before you complete you basic and advanced training.
For a young person out of High School or College, however, this is a more than a slogan...
the U.S. Military remains a great place to start (or at least spend 2 to 6 years). Not perfect, not high paid, and rarely filled with "Hollywood" moments, but still a good place to begin.
I do recommend one carefully consider the Reserves and National Guard, in addition to Active Duty. And remember that there are opportunities in
five branches of the Armed Services... Army, Navy, Air Force, Marines, and
Coast Guard.
In the Air Force, if you want to see a lot of the world and be on the "pointy tip" of the spear in the modern battle plan not just for a single operation, but all the time... Loadmaster is a great opportunity. A Loadmaster can be trained and qualified out of High School (you don't need the extra 5 years that pilots and flight engineers typically do), and we have Loadmasters in Active Duty, Reserves, and National Guard.
So what is a Load (that is our everyday term for them)? Simply put, the Loads are in charge of the cargo and people in our aircraft. They are the pilot's eyes and ears. They have a great deal of direct responsibility. They are Aircrew, and stay with the pilots, navigators, and flight engineers.
A lot is expected of a Load... we all rely on each other on the ground and in flight. You should have a good attention to detail, and be able to quickly and accurately work with numbers and calculations (checkrides test all of us on our aircrew duties), be able to read and understand complex regulations, and be able to improvise and think on your feet. You should not be afraid to carry and properly use a 9mm pistol. Most of all, you must have a professional attitude.
Strategic Airlift Loadmasters.... There is no other job in the US Military that will allow a 19 year old to see so much of the world so rapidly. If you like to fly, are relatively young, and want in on the action... being a Load could be just the ticket (no pun intended

).
Here is my plane, the C-141, during for Air Refeuling operations. It closing in from about 200 feet with a KC-135 tanker. The job of a tanker is to pass gas

. The refueling boom (top of photo) has been moved up to get a clear photo. The boom will be "plugged" into the little hole above the pilot's windows on the C-141. With Air Refueling, the US Air Force can deliver people and equipment to any location on earth (including Afganistan), in about 14 to 20 hours. The reciever pilot must fly the aircraft by hand (no autopilot, despite what Hollywood says) to an exact location (plus minus one foot) under the tanker. It takes about 20 minutes to get 130,000 pounds of fuel (20,000 gallons). BTW, it takes one AR (or two if weather is bad or carrying maximum cargo weight) to reach Afganistan from the East Coast.