What did Cicero think a good society was?

Cicero conceives of society primarily as a means to an end. And that end is the flourishing of the individual. Although Cicero himself retreated from society at certain points to engage in writing and quiet contemplation, his ideal individual is a sociable man, an active citizen involved in various aspects of public life. Society must be geared towards producing just this kind of man, catering to his various needs, both material and intellectual. It is only in society that the citizen can develop all his various faculties to their fullest extent.
Man's needs are greater than those of the animals. Whereas the beasts of the earth can be satisfied with the simple necessities of nature—such as food and shelter—man, as a higher animal endowed with a soul, needs more. It is only a well-organized, structured society that can provide man with his higher needs, whether it's for luxury goods, property, the arts, or intellectual commerce, the exchange of ideas. Without this association of men, there would be no cities, and without cities there would be no civilization as Cicero understands it, no laws or customs to regulate human life.