Navy = Care about their boats and have some aircraft (lots of helos). Spend lots of time on a boat with tons of dudes...could be a pus if you're a chick.

Army = Care about their tanks/infantry/etc....and have some fixed wing. Enjoy your one year deployment every 15 months.

Marine Corps = ooooaaaaarrrrraaaaaahhhhhh!!!!!!!!!!!!!!!!!!!!!!!! !!!!!

Air Force = Care about their planes and have lots of them.

Having said all that, join the Air National Guard and never look back! If I had a nickel for every time I've heard "should've joined the guard," I would never have to work again. I have never heard a guard guy say...man, I wish I would have joined AD.