Great question. It really depends on what you like to do. Above all, find what you like in life and do that. You should never pursue any career or position just for the money or the prestige because in the end, you still have to go to work every day and do that job. That said, I loved the law so I went to law school but, unfortunately, practicing law is not like it's portrayed on TV or like what you study in law school. If you like business, you should focus on an MBA. It's more flexible and can be easier to get a job in the business world. If you like law, focus on getting a JD. I have both degrees and I use both of them every day in my work as a consultant. I "speak" law and business pretty fluently which helps me understand my clients and their problems much better (both businesses and law firms).
Many schools also offer a joint JD/MBA degree. It's more difficult and more expensive than just getting a JD or an MBA degree by itself, but it's also cheaper than getting a JD and then going back later for an MBA (or vice versa). If you are serious about a career in business with a top company or consulting firm, don't settle for an on-line MBA. It's not the same and does not provide you with the same opportunities or connections.
Above all, get the best possible grades you can in high school and do lots of extra curricular activities (sports, theater, newspaper, yearbook, band, whatever). Use your great great high school resume and grades to get into the best college you can. Get the best grades you can in college and look for leadership, volunteer and internship opportunities everywhere. Then take that great college GPA and resume and get into the best grad school you can. By getting top grades and getting into top schools you maximize your opportunities when you finally get out. With a JD from a top school, you can get a job at the best law firms. If you get an MBA from a top school you can go to work for whatever top company or consulting firm you want. Bad grades and mediocre schools limit your opportunities.
A huge part of getting top grades from a top school is the connections you will make while in school. Don't forget that your classmates also have top grades and will be working for top companies and law firms. You can leverage those connections for the rest of your life. This will lead to clients for you, jobs for you, and all kinds of other help you can't imagine. So be a good networker. Create relationships and maintain them.
But above all, find what you love and pursue that. Face the fact that finding a career you love may not involve an MBA or a JD, but with those degrees you can achieve whatever you want in life.