Done the trip a few times however never had a lot of time for sightseeing :(
Nairobi>Arusha>Ngorongoro>Moshi>Kili>Bagamoyo>Dar>Zanzibar (don't miss zanzibar!)>south through Malawi>do some diving>Chipata>SLNP>Lusaka>Livingstone>VF>Kazungula>Chobe>etc, etc
Lots to see, lots to do, lots of...