Colter Bay is my favorite.

I've stayed in the cabins here 3 years in a row and now the camping sites this year (not RV resort) and I cannot get enough of this place. 

Camping amenities are nothing fancy, nor are they bad. The bathrooms next to the sites were clean and flush which was a pleasant surprise.

The site was somewhat level, could have used blocks but we are in a van and only stayed two nights, so it was not that big of a deal. 

Showers in the "Launderette and Showers" were decently clean, nothing to complain about aside from the odd closing at 8pm. (Not really a big deal, just need to plan around it if showers are a part of a nightly routine)