I always stay at
Grizzly RV Park in West Yellowstone. Two blocks from the West gate. They have four levels of parking spots depending on what hookups you want.
I have the NP lifetime pass. Best deal going. Here's the scoop on the
National Parks Senior Pass. Best deal in town. $10 lifetime pass if 62 or over, and you can buy it at any NP facility. I bought mine at the Wm. H. Taft Museum in Cincinnati. As you might expect, there was no line. :)
West Yellowstone is a nice town. They have the usual souvenir shops, but they also have restaurants, competitive gas stations and grocery stores. If you choose, stop at the Grizzly and Wolf Discovery Center in town. As close as you want to be to either animal.
BTW, if you go thru the West Gate in the morning the line isn't long. Most of the day trippers aren't there yet.