First, congratulations on having an idea of what you want to do as a career at so young an age. I wish I decided on nursing when I was a sophomore in HS instead of my early thirties.
The best advice I can give you is to speak to an Army, Air Force or Navy recruiter. Ok, now that I got the expected advice out of the way, here is a little extra.
Generally speaking, The Army is the service to go to if you are looking for reimbursement of education expenses you already have prior to entering one of the branches of the military. They have a health education reimbursement benefit that will pay off one third of your education loans per year for 3 years. I'm not kidding! You will be school loan free at the end of three years. As for the other benefits, If I'm not mistaken they're all just about the same when all is said and done. They may call them different things and pay them in different ways but in the end the amounts they pay towards your education are within spitting distance of each other. Also, If you ever wanted to go the CRNA route, the Army has the US Army Graduate Program in Anesthesia Nursing ([USAGPAN. [I highly suggest you Google this.I don't know how to attach links, or I would have, but you should take a look at this.] Though this is open to Army, air force and civilian applicants, a strong letter of recommendation from an Army Base commander can't hurt, and you won't get one of those unless you're in the Army
For what it's worth, I'm considering going back into the Service upon graduation (I'm a former Marine), and my choices in order are Army, Air Force then Navy. No disrespect intended toward the Navy-Lord knows we need'em,- but I've been on several deployments and I wouldn't wish ship life on my worst enemy-and I can be pretty vicious! Granted more of their nurses serve on land than ship, but the possibility of serving on ship dealing with (yeah, I'm just gonna say it) pain in the ***, immature and reckless Marines isn't really there in the Army or Air Force. I don't want to get into it, but just trust me-we always kept medical busy sewing us back up after taking on stupid dares and making stupid decisions-like "I bet you I can hold this blender blade still when you hit the button!" I. AM. NOT. JOKING! This is what you will put up with (along with crowded ship life with ZERO privacy). BTW, I was on ship when the "Blender" incident happened. And this isn't a rare thing with us (Marines) either...
Hope this helped, but remember that this is just one (amazing [lol]) man's opinion. Speak to the recruiters of all 3 branches to get a better idea of what they have to offer. Oh, just make sure you keep in mind that it is their JOB to recruit. THEY WILL FEED YOU HALF TRUTHS AND LIES, so look into their eyes as they answer your questions. It is usually not very difficult to read someones body language and tell if they're hiding something. Most of the lies they tell are lies of omission. Do your research on the internet first to get a basic idea of the benefits of the respective services, and draw your questions from that research.
Also, I just read the post above and have to agree that "Yes", the Air Force is known for having (FAR) better living conditions, and a generally better day to day life for their people than the rest of us. At least as far as enlisted's are concerned. As for officers-which you will be if you enter any service as a BSN RN, I don't know if this is true as officers even in the Marines had pretty good lives. But I won't be surprised if it were true for officer's as well.