I was there for the first time last week. It was pretty amazing.
We saw all the the major wildlife except moose. My favorite area was the west thumb and the grand canyon. Old faithful didn't do much for me but being YNP, you gotta see it. I didn't carry bear spray but I did carry a 40cal. Figured it to be more effective than pepper spray.
We also stayed on the grand Teton NP. We camped while on GTNP and YNP. I'd do it again but not jumping from site to site if I can help it.
We also left through Cooke coty/silver gate and took the bear tooth pass. Beautiful!! To say the least. We had a week....I wish we had 3.
