Hallowfall is as good as zones get in this game.
Isle of Dorn is nice, it’s fine, it’s generic and unspectacular, but not offensive.
Ringing Deeps and Azj-Kahet are zones I’ll probably never come back to after TWW is over.
Maybe not enough time has passed yet, but I haven’t wanted to go back to any Shadowlands zones either. Bastion and Ardenweald were lame. Maldraxxus was okay. Revendreth was nice but not worth revisiting.
I still revisit some of the Legion zones quite a bit. For how much hate it got, BfA had some great zones that I like going back to. Obviously Northrend and Outland had some great zones. AU Draenor even had some good ones.
Maybe something in me has changed and it’s not the game, but SL, DF and TWW don’t have anything like that except for Hallowfall.