Kanto and Orange Islands are kino.
Johto is a slog, with a lot of "character of the day" episodes where nobody really does anything, or catches anything new, but has a lot of great Gym and League battles.
Hoenn is okay. They dial back on CotD episodes, and opt in to do Contests and Gyms. It feels a bit more like Kanto, with a slightly larger focus on adapting the RS plot. The League and Gyms are kinda average. None of the battles really stand out. Also, Battle Frontier has great battles, but some of the non-battle episodes aren't too great.
Sinnoh has Johto syndrome where theres a lot of CotD episodes, but things actually happen in them such as evolutions or new captures. An even larger plot adapation focus here. Contests are flashy, Dawn is a great junior to Ash, and this is Ash at his best. He also has his best rival here. His Pokemon all have great personalities. Hope Torterra isn't your favorite tho, cause he's a fucking jobber. Tobias fuckery aside, this is easily the best League. Paul vs Ash is legit the best fight in the anime. Great animation, great pretense around their battle and just a fuckton of growth between Ash and Paul.
Unova is actually dogshit. Its every bad point about the previous seasons without any charm. Iris is insufferable, Cilan is Brock but worse, and the rival is just a worse bootleg Paul. Barely any attempt (if any at all, i legit don't remember) to adapt the game plot. Some Gym battles are okay but the league is GARBAGE. But Ash does get a Krookodile and that's cool. There's a shitty Orange Island knock off arc before Kalos with no gyms and a Charizard pandering episode.
Kalos is Sinnoh 2. Clemont isn't nearly as awful as Cilan, and Serena is an okay companion. Kalos has great focus on world building, and things feel natural. great Gyms, fantastic League (until the finals, which even has a phenomenal fight, if though the outcome is fucking stupid.)
SM and SS are both great series. Comment too long, gg.
