>>30662238First versions, it's second-place imo.
Black White gave you a good-lengthed journey before beating N & Ghetsis, then got.... admittedly, more around a third or a fourth of the region (given "simpler" routes, less dungeons, and little story). The hide & seek with all 7 sages, the sunken temple, Giant Chasm, hunting your Genie. Cynthia's Villa. Black City/White Forest probably being the best non-frontier facilities besides maybe PWT. And lastly, the proper claiming of the E4 and getting your time to actually fight Adler.
Kanto basically had 1 cave.
Johto... Kanto was really the latter 38%, with Mt. Silver & Red as the Last 2%.
Hoenn had Fug, maybe the routes down to the Regis and their BS, and your roaming Lati@s.
D/P had the shit island.
Kalos had Looker Quest (which as shit), hunt a bird, mewtwo, Zygarde, and the 2 facilities in your one post-game town.