We stayed at a back in site at Yosemite Pines (with no reservations) in 2011 & liked the site. Nothing fancy, but quiet (except for the acorn woodpeckers in the tree next to our site) & uncrowded. I guess it depends on the time of year - we were there in the end of May.
My favorite way to visit Yosemite is to stay in Lee Vining. Of course Tioga Pass needs to be open & is is a long drive, but I like visiting Mono Lake
& the Bodie Ghost Town
, both near Lee Vining. There is a commercial campground in Lee Vining (Mono Vista) , and a couple of boondocking sites around the lake.