I guess it's like comparing apples and oranges to me there are so many different types and levels of accommodations. Experience-wise, Grand Hotel, Mackinac Island. Truly like stepping back into bygone era. The dining from the decor, to the service to the food itself is something truly magical that even Disney can't touch. I feel lucky I've had a few opportunities to stay there in very low low season!
For us, I would say this one is at the top of my list too. We stayed one night at the Grand for our 6th wedding anniversary back in 1981. I remember paying the "outrageous" cost of $139/per night. We had a back-facing room, but oh, it was so pretty. And dinner in the dining room, with the elegance, the orchestra, the servers dressed so nice, and the outstanding food. The public areas of the hotel were so nice, and that wonderful mile-long outdoor porch with rockers. Such a unique experience. Sadly, I refuse to pay what they charge now so we haven't been back. I might go in the spring, as their rates are quite a bit more reasonable then, but DH is a farmer so we just can't count on getting away during the month of May.
Other great places for us have been Port Orleans Riverside at Disney (have stayed there 4 times) in the mansions section. We also love, love, love the Drury Inn & Suites hotels. We always get a suite and they are wonderful, with a door separating the living area from the bedroom (much prefer that, rather than just a large 1-room "suite") plus they have a wonderful breakfast AND they serve great snacks and drinks from 5-7 p.m. every evening. Hot and cold snacks, with some items (meatballs, pastas, baked potatoes, etc) being more like a meal rather than a snack. And each adult is allowed 3 free alcoholic drinks.
We enjoy Hilton properties too, especially when we can get a room on DH's Hilton Honors points. One being the former Thomas Edison Inn, now Doubletree, in Port Huron. Another favorite is the Chippewa Hotel on Mackinaw Island, we like having a top floor room on the water side and love having morning coffee out on the balcony overlooking the water with the ferries coming in and freighters gliding by and watching the sunrise.