If we're voting on the merits of the lands including their attractions I'd give it to Galaxy's Edge, but Rise of the Resistance is going most of the work there. Without Rise, the land is very large and expensive and woefully lacking content and soul. I'm not a Star Wars Fan, though I don't particularly hold that against the land.
If we're voting on the merits of the environs of the lands themselves, attractions aside, I'd give it to Pandora. The created environment is sui generis, there's atmosphere, there's intrigue . . . and then at night? Hoo boy. The land isn't without its issues, but seeing it the first time made me excited about the potential for the future of WDW. I am not an Avatar Fan, but hold no grudge.
I can't think of any criteria by which I'd give it to New Fantasyland. There are parts of it that I like, but I don't know if there's anything that I love. Overall the project is a swing and a miss. Where Galaxy's Edge lacks soul it at least makes up for it with ambition - New Fantasyland tries to do Quintessential Disney and falls on its face, it seems to totally misunderstand itself. I'm a BIG Fan of Classic Disney Animation, but I don't consider my bar to be especially high - in my judgement, DL, DLP, and TDL all still have richer, fuller, more dynamic Fantasylands. They ooze warmth, and New Fantasyland is cold. What a misstep.