With three weeks you should really consider varying your itinerary. If you want the emphasis to stay on game viewing and are willing to get on a plane, at least head to a different area. Otherwise, you're just going to see the same animals and scenery over and over again. The water-based activities of the Okavango Delta in Botswana would be a great compliment. Or you could see Victoria Falls.

For something different from game viewing, you could head to Cape Town and/or the wine region.

I think we all agree that a little variety would be nice but you could still keep a very lesurely pace with 3 weeks.

A great website for Africa forums is fodors.