Callisto Colony
Callisto seems like the most suitable of the major Jovian moons for human settlement. It orbits just beyond Jupiter's main radiation belt, has abundant water-ice, and is very geologically stable. It even has a magnectic field but I'm not sure how strong it is and how much protection it might give from solar, jovian and interstellar radiation. Yeah Callisto is the least interesting of the major moons but could serve as an excellent base location.