Quoted By:
Gen 1: Pikachu (Red's team has Pikachu and all three starters, suggesting that Yellow is canon)
Gen 2: Typhlosion (Feraligatr's more fierce appearance fits Silver the best, the kid who looks like Gold in Pokemon Chronicles had a Typhlosion)
Gen 3: Sceptile (May had a Torchic in the anime, she has the starter strong against yours in the games)
Gen 4: Torterra (Dawn had a Piplup in the anime, she has the starter weak against yours in the games)
Gen 5 (B/W): Samurott (Bianca has an Emboar in the anime, she has the starter weak against yours in the game)
Gen 5 (B2/W2): Emboar (Hugh has a Samurott in the anime, he has the starter strong against yours in the game)
Gen 6: Chesnaught (Serena has a Fennekin in the anime, she has the starter strong against yours in the game)
Gen 7: Decidueye (Hau is a faggot so Primarina fits him well, Kukui is a wrestler so Incineroar fits him well)
Also only male characters are canon, which is why Ash remains the protagonist in the anime.