Definitely the moon. They would have to demonstrate that they can put a self-sustaining base up there, because that's what it's really about. You can't keep on shipping oxygen and water up there, that would have to come from the moon itself.
BTW, I very much doubt that it would be the US putting the base up there. Right now the Chinese are hellbent on making their mark in space, and a moonbase would be *the* achievement.
rumborak
A permanent base faces some other challenges.. namely... what you do with the humans there. Do you keep moving em back and forth, or get permanent volunteers?
I think you would have to do something along the lines of rotations like they do for the ISS.
Ya, but that get's costly. ISS is much closer. Really though, when I think about it, would it be
that hard to find people who want to colonize the moon?