Most of you guys aren't realizing that SA and CA cichlids are very different fish, and there are lots of other things to consider (aside from the obvious that they come from different parts of the NA/SA continents...), I'll try to explain:
When someone uses the term "SA cichlids" they are, for the most part, referring to relatively peaceful fish that do well in community setups and at a low ph/kh. These include severums, satanoperca, geophagus, many other less known species, and all the other smaller SA cichlids in various other genuses (including tiny cichlids like apistogramma). They are rarely aggressive enough to cause deaths, most do quite well with other, smaller fish (although my apistos hate Corydoras! There are always exceptions and research should be carried out on particular species).
When someone says CA cichlids, they are generally referring to fish that fit in the group of what people call aggressive cichlids... Convicts, red devils, green terrors, jags, midas, just to name a few of the more well-known ones. They tend to be much more aggressive, and will often kill other fish if proper research into housing/husbandry isn't carried out They also generally prefer a notably higher ph/kh/gh. They tend to be very interactive and have lots of personality (same can be said for some SA cichlids too).
To make matters confusing, we have exceptions. Oscars are actually south american cichlids, but grow very large and can sometimes be aggressive. We also have some oddball exceptions like festae, or the red terror, which are SA but are similar in behavior and size to CA cichlids.
To make them even more confusing, we have crenicichla, aka pike cichlids and cichla aka peacock bass. Both of these are predators, and have unique requirements. Heck we even have angelfish and discus! Most people don't even realize they are even cichlids, but all are technically cichlids found mostly in south America, but are so different people refer to them specifically instead of what they refer to when they use the term "SA cichlids."
So you see it's really impossible to answer the broad question of CA/SA cichlids vs African cichlids. You should state exactly what you are looking for in a fish, and what size tank you have, and can get better suggestions from there.