Most African wild game are good to eat, as long as it is cooked properly. Some of the best are eland (as long as bulls are not in the rut). Also desert type game like gemsbok and hartebeest are excellent. Sable meat is good also. Of the smaller animals, most are good to eat, particularly reedbuck. Nyala are also good. A lot depends on the condition of the animal, and if it is shot well and not wounded before killing.
My favorite African wild game offal dish, is actually flame grilled Impala liver. Among game birds, I absolutely find guinea fowl potjie to be heaven on earth.
The only African game which I absolutely disgust... are spurwing goose & waterbuck. A waterbuck, particularly an old one, has a very oily substance that gets in the hairs of the skin. When skinning the animal, great care must be taken to avoid getting the hair or oil on the meat. An old trophy bull does taste a bit strong, but a young waterbuck tastes quite fine.
Cape buffalo is coarser than bison and tougher. However, the tenderloin (or fillet) are excellent when seasoned simply with coarse grained salt and grilled over the open camp fire. Especially with an ice cold African Castle Lager to wash it all down with.