ADSL is the best option, as its the cheapest bandwidth, however you can not be mobile with it so I guess the question comes down to what do you need your bandwidth for, if mobile then 3G is the way to go, if not then ADSL. Next problem is does Telkom have ADSL in your area or not?
Currently there are only 3 HSDPA/3G players in the market, Vodacom, MTN and Telkom 3G and the best pricing wise currently is Telkom 3G, Telkom 3G supports 7.2 meg and has a 30c per meg out of bundle rate, compared to the others this is awesome.