I don't recommend any of them, to crowded and to close together for our tastes. We just returned from three weeks in the west and stayed at Buffalo Crossing RV Park just outside the west entrance in west Yellowstone, MT. Worked very well for us. Everything we needed was within walking distance. The west park entrance is 1/4 mile from the RV park.
I also recommend getting started touring the park early, early. I mean like 5:00 am. We were up at 4:00, headed into the park by 5:00 and back at the camper by 2:00ish every day we were there and we always beat the crowds. Between about noon and 5:00 pm it gets really crowded at most of the sites and traffic can back up for miles.