You guys are forgetting Rayquaza, Eevee and Gardevoir. These Pokémon are also sometimes allowed to exist...
Pokémon company also vaguely remembers Pokémon by the name of Gengar and Mew.
That's about it. The other 700+ Pokémon aren't really significant. Like Arceus for example.
Don't forget Hawlucha. That thing has cards everywhere