I'm mulling Constitutional law and corporate law, as well as becoming a prosecutor (district attorney, asst. AG, etc.). Maybe a defense attorney. I just don't see myself being a trial lawyer--they're way too slimy.
Nor as a public defender--I'd be inclined to take many cases pro bono or to work for the state at a salary. Both of which just don't seem right for whatever reason.
When you are in law school, you will take law classes in a lot of different areas. So you will be able to narrow down the areas of law that you like and then decide which one(s) you want to go into.