How about going on a city tour with your family or your visitors now and then. There are companies that organise great tours of Johannesburg either by bus or walking tours to unusual hidden parts of the city. Have a look at the listings below to see if they interest you.
Joburg Inner city/CBD tours, events, experiences, walking and public transport tours, Soweto and archaeological tours
Contemporary & historical art museum/gallery
Visit day trips
for activities to take part in and places of interest to go to with your family.