>>55416546My personal favorite is Sinnoh as I feel that of all the regions, it has the most realistic environment with Kanto/Johto as a close second.
Hoenn and Unova are fine but they have some drastic temperature/biome shifts where Sinnoh's environments transition smoothly into one another. The trade off is that Sinnoh feels more real but less exciting but I can understand why some would list Hoenn as their top choice.
Kalos is alright but it feels too much like a diorama for me. Most routes and towns are all so small and compact with Lumiose being the only place that comes across well. Alola was a small step up from Kalos but not by much.
Galar is the worst to me because the main part of the region is depicted as only having Gym towns. This creates a weird uncanny valley kind of experience where it just doesn't make sense for the only towns in the regions to be gym towns and the rest to just be unsettled land.
Paldea has the best map of the 3D games and its environments do transition well into one another. It does feel a little empty for its size though. I think that it would have helped a lot if those Team Star bases were actually small towns.
My final ranking would have to be Sinnoh > Johto > Kanto > Hoenn > Unova > Paldea > Alola > Kalos > Galar
