I grew up on Navy and Marine Corps bases and served in the Air Force and Army. I also served along side some Marines and Navy when I was on active duty. I think I can give some of the pros and cons of all of them.

The Navy probably has the best technical training and the best food. Especially aboard ship, hours are long and quarters are cramped.

The Air Force has pretty good technical training, the best quarters, and decent food. It is the least physically demanding unless you are a combat controller or air rescue.

The Marines have the best combat training and since they are part of the Navy, pretty good food. Their quarters vary, depending on whether you are Marine aviation or ground pounders. The Marines love PT and pain.

The Army is just big. It is a huge bureaucracy and all of the above vary with the unit. Some get good chow (82nd Airborne eats well), some don't. Depending on where you are assigned, you may live in the woods or desert most of the time, or in decent quarters, but not nearly as good as the Air Force. I spent nine months of my first year in Germany living in my tank in the field. I was always with the infantry and they fed me better than my Armored battalion did back in garrison. If you are in the combat arms, life will be fairly rigorous and physically demanding.

So have fun. Whatever branch of service you choose, it is a worthy and character building experience that all fit young men should experience.