We just returned from West Yellowstone and there are many restaurants to select from. We ate out only a few times but this is what we found:
Wild West Pizza - the pizza was very good; we had the speciality pizza, Sitting bull - lots of toppings and crust was great. We also had a side salad where we ended up with just lettuce/greens. Turns out you have to ask your server for toppings on your salad. Hard to do when you don't know
Gusher - we again had pizza (we liked the pizza at Wild West better). The toppings were skimpy and the crust was thicker but not quite done. We also had a french dip and hamburger sliders that were great.
Arrowleaf ice cream - good ice cream and one of the better priced places (there's many ice cream places in town)
Beartooth BBQ - great BBQ! We had the pulled pork and beef brisket and they were excellent. Casual cafe and the servers did a great job.
Woodside Bakery - this is a wonderful place with many delicious goodies. Don't miss it.
We also ate at the buffet in the Yellowstone lodge at Old Faithful - the prices are about the same as in town and the food was ok.