If you want to be in the center of the park, Fishing Bridge is your choice. Otherwise, Grizzly is great - and convenient to the park entrance. Really an excellent choice if you plan to spend the bulk of your time touring the park. We've stayed there multiple times. We have also stayed at the older KOA (there are now 2, both west of West Yellowstone by a few miles) - years ago - and at Henry's Lake SP in Island Park, Idaho. Electric-water connections there only, and a dump station. Great scenery there, but it can be windy. If there aren't fire restrictions in place, you can have a campfire at your site. Not much shade, though, and sites aren't private, though they are spaced pretty well.