The Pines Campground
The Pines Campground is largely open and level, and though privacy isn't something you generally expect at a campground to begin with, that goes double at The Pines.
The Pines has eleven campsites (thirteen if you count the adjacent Pines Group Campground), potable water available through an outdoor faucet, and four pit toilets. The campsites, which cost $16 ($70 for the larger sites at the group campground), have picnic tables and fire pits.
The campground is just down the road from the Groveland Ranger Station, so you don't have far to go to complain if there's no toilet paper or you wish you had more rules to follow. If you've got that kind of time, though, take a few minutes instead to pluck up a few of the Star Thistle plants (be sure to get the roots) that are infesting the area.