The place
Mikumi, in short.
Mikumi is the southern park you can actually drive to. The TANZAM highway from Dar es Salaam to Zambia runs straight through it, which makes it uniquely easy to reach and gives it a problem no other Tanzanian park has — traffic, at speed, through a national park.
The Mkata floodplain in the north is the heart of it, open grassland with scattered acacia that people routinely compare to the Serengeti in miniature. Elephant, buffalo, zebra, wildebeest and giraffe are all straightforward, and lion are regularly seen on the flats.
It borders Nyerere to the south and is genuinely part of the same ecosystem. Treat it as a first or last night on a southern trip rather than a destination in itself, and it earns its place easily.