Walk, mountainbike or drive (4x4) in the Groenkloof Nature Reserve, the second oldest nature reserve in the world. See giraffe, antelope and many other animals. It's located between the city center and Centurion.
Visit Hartbeespoort Dam. There are hot air balloon rides over the Savanna, a cable car, a golf course and watersport.
A picture of a hot air ballon, taken from a second ballon
The largest shopping centers are :
Menlyn in the East. It includes a roof top drive in theater.
Brooklyn in the centre with it's art galleries and a movie theater for independent films.
Kollenade in the North with it's ice rink and other entertainment.
Centurion Mall on the Southern side of Pretora
The renowned restaurants include Cynthia's, The Hillside Tavern and Pachas. There are also many franchised diners throughout the city.
The nightlife is concentrated in Hatfield (near the university) and Menlyn Square.
Being the capital, there are many posh hotels (including the Sheraton) and guest houses.
The Farm Inn out on Lynnwood Road provides a uniquely South African experience.
Fly out of Johannesburg International Airport.
Rent a car from one of the many outlets. Note that the N1 North is now a toll road, so have some cash on hand.