I stayed in Many Glacier. Sites are close together and on the small side, but that didn't bother me. Plenty of wildlife around the CG while I was there: deer, rabbits, etc. Towering mountains all around.
On the west side, I wanted wi-fi and electric so I stayed in the private Glacier CG located a mile or two from the W entrance. But I spent some time around Apgar and it seemed very nice there under the big trees with Lake MacDonald so close by; one can walk to the dock and rent a canoe, or buy an ice cream cone.