We love this state park. We frequent it regularly. The sites are all mostly level (front to back and side to side), the facilities are well maintained and the rangers patrol regularly.
This is a very wooded campground, offering lots of privacy. There's a nice playground that my youngest is a big fan of. The campground is also a short drive from Poplar Tree Lake which offers boating and fishing (kayak rentals are available, or you can bring your own); no swimming area though.
Some of our favorite sites are 7, 8, 11, 12, 13, 25, and 26. These are in all in the two smaller loops, though the main loop sites are quite nice as well, they just don't feel quite as secluded.
Also, make sure to check out the Shelby Forest General Store. They sell little bit of everything, including great food if you don't feel like cooking at the campsite!