what's the degree for me?

Hi all,
Well, considering that right now in my life (single, working, not much else) I figure now would be a good time to start taking some grad courses. Since I would eventually like to work in research one day, I was wondering what advanced degrees do you see colleagues pursuing or you yourself are considering or doing? I have taken one course in Masters of Public Administration which I enjoyed but am concerned as to how valued it would be viewed. I think an MBA would not be as enjoyable to me. Any thoughts would be appreciated ! T.