Gen 1 easily has the best Pokémon batch. The concentration of 10/10 A+ designs in it is significantly higher than any other generation. Beedrill, Slowpoke, Gengar, Mewtwo, Arcanine, Gyarados, Starmie, Charizard, Hitmonlee, Alakazam, Machamp, Snorlax, Kabutops, Aerodactyl, Lapras, Victreebel, Tauros... damn that's a long list and they're all timeless and amazing designs. And it's only off the top of my head and a lot of other Kanto Pokémon are still easily 9/10 or 8/10. If I had to make a list of 10/10s for Sinnoh, Alola or Galar I could only name like 2 or 3 Pokémon in comparison.