>>39789162>Sinnoh>Johto>Kalos>Hoenn>Alola>Kanto>UnovaSinnoh is my favorite because all of Ash's opponents aside from Tobias had been established since the beginning of DP instead of almost all of them being introduced slightly before the league starts. Ash bringing back his old Pokemon is something they should've done with every league from DP onward. Ash vs Paul is hands down my favorite battle in the series and while Tobias was complete bs Ash at least put up a good fight against 2 legendariers.
