Minibus shared taxis don’t have stellar road-safety records, but fares are cheap and the network is comprehensive. The downside is that journeys can be slow, with constant stops and long waits to fill the seats.
Larger cities have private taxi services. They are much more expensive than shared taxis, though it is important to remember that the price is negotiable. It's best to ask your accommodation to phone for a taxi rather than hailing one on the street – the vehicle will likely be better quality and you can ask your accommodation for a reputable company.