Table Mountain via the cablecar. The waterfront in Cape Town (a bit of a tourist trap but worthwhile) Shark diving in Gansbaai, whale watching in Gansbaai (August,September, October) Kruger Park, wildflowers in Namakwaland (Spring in S hemisphere) Tsitsikama Forest, Addo elephant park. about 6 years ago
Cape Town is beautiful.
The Kruger National Park is a must.
A lot of tourists go on tours of Soweto.
There are reserves where you can play with baby lion cubs etc. Johannesburg has a lot of top class restaurants with great food and although expensive for someone earning rands, it's a steal for a tourist travelling on euros etc. about 6 years ago