>>29549623B2/W2 Unova probably has the most to explore in a single Region, despite the initial linear/circle exploration. It's incredible how much content are in those games.
Sinnoh is second biggest, especially with Stark Mountain thrown in.
People will meme about "e-empty Regions!!11!", but HG/SS's Johto/Kanto combo did have quite a damn lot to explore, spread across both Regions.
I'd say Alola probably fits here in terms of size
Then Kalos, Genwun Kanto, and Hoenn as the smaller "standard" Region sizes. (I don't think Alola looks to small, just spread a bit thin across the four islands. It's definitely smaller than the "BIG" Regions though)
Hoenn is boggled down by just how much of the Region is the near-empty water routes. (The latter half of the region has fucking 7 of them back-to-back, and that's not even mentioning the completely empty Dive sections)
