Which military branch is best for me?

I would first recomend the Air Force, as it would look very good on your resume if you have previous experience working on anything to do with aircraft. Navy or Army could both be good alternatives, as they both have good engineering programs as well. Make sure you know that just because you go to your recruiter and tell him you want to work on planes, doesnt mean that is what you will start off doing. You will be starting off at the bottom, and will eventually get to where you wanted to be. (I knew a guy that went into the Navy in order to train to be a plumber, and right after training they put him on a ship doing nothing but cleaning the bathrooms for about a year). Not mention, if you finish so many units of school, you enlist as a higher rank, and you can do more school after you get out.