Pros
Great opportunities for education: The Navy has a Tuition Assitance Program: That will pay for 100% of your classes after hours as long as you make a B or higher. The GI bill has also drastically improved this year providing more funding for college once you get out of the military. Leadership responsibilities: It is up or out, you have a certain amount of time in a paygrade to prove that you are ready for the next paygrade. So every year or two, the amount your responsible for increases and the number of people you are in charge of multiplies.
Cons
Deployments that take you away from your family for six to 12 months. The locations you can deploy too are dangerous and the quality of life is very poor. When you are in the military, you are US property. The military will tell you what you can wear, what you will look like, how you will speak. They will control were you go on vacation and can limit your vacation time based on their needs. You will have to move your family every 3-4 years and make it hard settle down in one place. The military doesn't give bonuses or overtime pay, so they can take advantage of how much you work.