WL is probably my personal favorite, but exploring for yourself is half the fun. If I were you, I'd avoid looking at any (more) photos ahead of your visit, so that THIS year's decorations are a bit of a surprise.
I would also say that where you visit depends a bit on where you are staying and the rest of your vacation/how much of your visit you want to spend visiting hotels. It is fun to spend a non-park day touring hotels, but if you are trying to combine park touring and hotel visits on the same day, I'm not sure it necessarily makes sense to spend a ton of time going all the way over to AKL by bus if you are only going there to see the decor. For me personally, I tend to prioritize the monorail loop, where I'm staying, and the Boardwalk/BC/YC loop. Though the other hotels have nice decor, visiting more of them tends to take quite a bit of time, especially if you are relying on the WDW transportation.
Ft. WL is worth visiting if you have never been, but it takes a good chunk of time. Night is best.
If seasonal decor is a priority, I DO suggest an evening in Disney Springs, and consider doing the holiday cookie scavenger hunt if they offer it this year. (you get a cookie if you find everything). Amorette's always has fun seasonal dessert offerings.
Last, if you enjoy seasonal decor, some year make plans to see the hotel Easter eggs around Easter. GF always has a large display (or has in prior years), but the other deluxe hotels also have some really neat eggs. The eggs at CR are a little harder to find. Some of them are located inside Steakhouse 71. Bwk usually has a good number of them. The number of eggs/locations vary from year to year. Though I should add, Easter is not celebrated at WDW nearly as much as Christmas or Halloween.