>>37037081Buneary and Riolu.
The main reason Pikachu and Eevee were chosen, shown in part by how they advertised them, is because one is popular with boys and one is popular with girls while both are also still decently popular cross gender.
This is also why you'd definitely see Pichu and Togepi for Gen 2 - Pikatwo versus Misty's fairy. Marill being a bit of a second Pikaclone is out of the running because it had basically no stage presence in the anime and is too female seeming. Especially with the rabbit evo.
Pachirisu is still a more cool/male oriented one like Pikachu and it will DEFINITELY be Riolu set up against it which is also obviously more cool/male oriented. Buneary is the only decent option for girls in the basic Sinnohcentric species.
Emolga might be the Gen 5 pick because of how it was played in the anime as a girl but Pachirisu won't be the Gen 4 pick unless they're really retarded.