Since Mewtwo was available in Generation 2 and is also part of the regional Pokedex, I would say that Mewtwo, with 154 base Special Attack, has the highest of all the Generation 2 Pokemon.
However, the highest non-legendary Special Attack stat goes to Alakazam, standing at a whopping 135 base Special Attack.
The highest Special Attack stat for the Pokemon that was introduced in Generation 2 goes to Espeon at an impressive 130 base Special Attack.
As for Attack, the highest Attack stat that was introduced in Generation 2 is Tyranitar's, who stands at a beautiful 134 base Attack. It's closely followed by Ho-oh at 130 base Attack. :)
