I quite liked Skukuza Camp for its nice facilities: the swimming pool is really pleasant even if it is crowded in high season. Also, for its mini-market, ATM, restaurant, filling station...
The camp is well situated for safaris, as it is very close to the prestigious private Sabie Sand reserve that is well-known for its concentration of lions and leopards, being simply separated from it by rivers (no barriers).
They are accessible to all budgets (21 pounds for two hours), it really is the opportunity to go into the bush with a pick-up and rangers who will explain the life of the animals to you, rather than with your own car, in which you are much lower.
The cheap accommodation at Skukuza is very pleasant. On the other hand, the camp is very big, it is a bit of a "factory", so do not expect to be in a cozy atmosphere! In the morning, there is a crush to exit the camp when the gates are opened.