I'm active duty Air Force - have been for 8 1/2 years. I'll piggy back off what everyone says....though by now, your probably already in.....
It's a decision you are either going to love or hate based on what you do or where you go. I'm on my third base and overall, I LOVE my job.....I just hate the people I work with and the jet I'm stuck working on. Many people join because of the economy and lack of job security then realize that it wasn't what they should have done. I did it cause 1) I love my country 2) I hated where I was in life 3) I have a family and wanted better benefits than what the job I had was offering 4) I wanted to see the world 5) it's paying for my bachelors and soon I'll be starting my masters! I say go for a job that is going to suit you and your future goals. My military job could help me to work for companies like Lockheed or Boeing when I get out if that is what I wanted or I could further that experience by going to school so that I could be a contractor when I retire and bring in some nice cash if I wanted. Needless to say, once I retire, the only time I want to be near airplanes is when my rear is sitting inside!
I can say I don't regret it....even though I've seen more injuries from this job than I ever did in my first 21 years of life but at the same time, I've seen places I never thought I'd see and I don't just mean lots of time in the sand box. I spent 5 f**kin amazing years living in Japan, a year and a half in Texas and I'm going on over a year and a half where I am now. I have gotten to see Thailand, Germany, and the Canary Islands in addition to the sand box. Looking forward to one day heading to Europe and since both the hubby and I are military, we have a pretty good shot at that. I know one huge drawback for people is being uprooted at anytime and not seeing your family for extended amounts of time - which was fine by me and my extended family as they had all been in one branch or another of the military. Granted, I've got kids and a husband so being away from them for long amounts of time does suck but with Skype and email....I can talk to them anytime.
If it's really your plan, do all the research you can before joining so you can be educated about what you will be doing...then go for it. But don't go in without researching and knowing exactly what you are getting into. You can't just up and quit the military - Uncle Sam will own you for a certain amount of time.