Apologies in advance for the length, but I hope to give you good specifics.
Not my own experience, but my stepson's.
He had a rough upbringing, his father was "not a respectable person," and even as a 4-year-old he knew it. His first stepfather wasn't much better, although not violent, he was just indifferent to his stepkids in favor of his own. Blatantly.
So, he grew up with a bit of a lack of respect for male authority, and a bit less respect for his mother. He loved her more than life itself and would do anything to help or protect her, but he had no respect for her mores, rules, history, etc.
When I came into the picture, it took him a couple of years, but he discovered that I meant what I said, kept my promises, and even though I didn't keep them on his preferred timetable, I
did keep them. He gave me the "You're not my dad!" speech
once. My response was "Yes, we can tell because you're not on the floor bleeding." I never heard that again. So he learned to respect me, but still mostly when it was convenient for him to do so.
He never learned patience, he never learned what I would call good discipline, and he never learned responsibility for himself and what he's said and done. He would always say what he needed to say to whoever he wanted something from, in order to get what he was wanting, and then it was forgotten.
Needless to say, we were shocked and a bit frightened when he came home from school one day in March and said he'd committed to enlist in the Army after graduation. With his history of rules-bending, lack of respect for authority, and inability to face the music for himself, we saw Leavenworth as the only possible result.
He heard nothing the recruiter said except $10,000 signing bonus, choice of assignment, blah blah blah. I kept trying to remind him that the recruiter was a used car salesman, and the Army was a '68 Rambler. Of course he's gonna dress it up a bit.
Well, the day comes in June to go to Montgomery for the physical and the assignment, and he calls me and says the jobs his recruiter promised weren't available. There was no medical lab job, there was no $10,000 bonus, the best he could do was gunner in a 2-seat chopper. I reminded him of the used car salesman, told him not to sign, but to bring the papers home to discuss with family. He called back 15 minutes later, had his lab job, had his bonus committment.
The Army transformed him. Yes, that's what they claim they do to youngsters, but they really do it. The soldier has to want to succeed, but every opportunity is there. The Army does not want losers, they do not want cannon fodder to send over the hill to take enemy fire until the hill is taken. They want productive, intelligent, thinking soldiers who can learn the system and play their part. My son kept telling me the things he learned, how soldiers become worthless if their unit knows they can't be counted on, if their actions are not above-board, if their word is no good. He went on about the principles and values drilled into the soldier along with the physical training and the fighting skills. Most of these things sounded familiar somehow, but at least someone was able to teach them to him at last.
My son found his niche and learned the rules. The "networking" skills that made him so popular in high school (everybody's friend, even though most knew he'd bail on them in a pinch) set him in good stead with the Army.
He graduated Basic Training with the highest score possible on the physical training regimen (running, push-ups, situps.) He was near the top of his class academically. 9-11 happened while he was in basic, so suddenly being in the Army in a real war became a possibility.
He had a year of school for training as a medical lab technician, then a year of working at the Army hospital at Ft. Sam Houston. Once through that, he deployed for a year to Iraq. He got married before deploying, and his daughter was born halfway through his tour. He was able to come home for that, and see her born.
On coming home he and his wife (also in the Army at this point) were stationed in El Paso, and he was offered a program to de-enlist and join ROTC to finish school. He graduated UTEP December '07 in the top 2% of ROTC graduates. Not 2% of UTEP, 2% of the United States! Choice of assignment, he selected the Old Guard at Ft. Myer, Virginia, and is serving there as an officer. The Old Guard is a special, traditional unit. He has tailored uniforms, even as the greenest lowliest office of the unit. When weight training and hand-to-hand workouts (he's an instructor in that!) bulked his shoulders up, he got new uniforms, even though it had only been 3 or 4 months since his originals. He was issued a saber; you should have heard that phone call! "Dad, they gave me a saber! A saber! What are these guys thinking!!!!" Their appearance is so important that because his glasses interfered with the correct fit of his cover, they gave him LASIK to correct his vision. This is a special place to be, and it's his first assignment as an officer! A lowly 2nd Ell Tee!
His "network" from San Antonio and El Paso hs resulted in an offer from West Point to join their faculty at the end of his time in Ft. Myer. There would be some study time beforehand, but it's a genuine offer.
Of course I'm bragging just a bit, being quite proud of him and his accomplishment, but the point is that anyone with a lick of sense and who puts in just a modicum of effort can succeed very well in the military, and the training applies to thousands of civilian jobs, or you can make a very nice career out of it.
I myself never served, and I regret it. At the time I graduated high school, though, military service was not something one aspired to. It was the end of the Viet Nam war, and soldiers were "baby killers" or mindless automatons, brainwashed into becoming murder machines. I bought into that, and truly wish I had seen better.
As to which branch, my personal preference would have been naval aviation. I can't see myself in the Army, and the Air Force is where guys go to learn to be airline pilots.
Not true, I know, but fun to say. Any of the branches would serve you well, providing you applied yourself fully and took advantage of opportunities as they present themselves. Training is free. School is free. Medical care is free. Housing is free. Food is free. And you get paid, too. A little bit at first, but it goes up with good rank. An E-3 can't live like his friend from high school who went into his daddy's insurance business, but it comes around soon enough.