Where is a place you've been and would really like to return to and spend more time?
For me, I always enjoy Zion NP, but I'd say Glacier NP because when we visited it was too early, the GttS road was still closed, and it was very overcast and we barely saw much. My wife would probably say Rome because our stay there was quite short though we had a solid tour.
We have a tenth anniversay upcoming and I offered to take her to a really upscale restaurant and she suggested a brief tour of North Georgia, again, which I planned. She likes Dahlonega, and can even pronounce it now. We're also staying in Blue Ridge which I don't know at all. They have a train ride there we might do though it's a bit pricey.