Hmm. Astronomers? Near a star there's background light (zodiacal light from sunlight scattered off or re-emitted from dust; also UV light scattered off hydrogen and helium.)

In very deep space, tidal forces are low (stellar tidal forces dominate vs. galactic tides out to a few light years). So if for some reason you want to be enormous featherweight structures, out there is the place to be.

Or the old Poul Anderson idea of a free planet being heated up until it has an atmosphere, to act as a giant low cost radiator of industrial waste heat (or, just using mass quantities of ice as a heat sink until it's all melted.)

Mars-sized planets in interstellar space could hold 3He in their atmospheres, and we all know how valuable that isotope would be. ;)