1) Why did you join up?
I did great on my college boards tests and had plenty of big schools that I could have chosen to go to. Choose to go and become one of Uncle Sam's Misguided Children

over the other services top programs I was offered because of the greater challenge, tradition, honor, and decication the Corps has.
2) What did it do good for you?
It teaches discipline, honor, and dedication and will give him a much greater sense of accomplishment and self worth.
3) What did it do bad for you?
Nothing.
4) Do you recommended any branch more/less than another? He was in AF ROTC for a year in college and my father was in the AF, so he's leaning towards it, but apparently they are having some severe $$$ problems.
From what I have read on what you posted about your son I would suggest the Marine Corps first. The discipline and sense of tradition the Corps has will go a long way in helping him out. Longest and toughest basic training. Despite the belief to the contrary there are quite a number of good job opps in the Corps.
After the USMC I would suggest the USCG (United States Coast Guard) An extremely under appreciated branch of service that it also heavy on disicpline and toughness and has some excellent programs. Also the most "active" of the branches, whether it be in peacetime or wartime ,as they have functions that serve both the military and civilian world.
After that the Army or navy is an either/or situation IMHO. They are both excellent branches and what your son would be interested in for a MOS would be the biggest difference.
Air Force- Shortest basic training and the least "strict" of the military branches. Still a great branch with excellent job opps, but IMHO not what you are looking for in this situation.