Vaporeon because it can learn more than just water type moves and it has great stats.
I think eeve is a trade only Pokemon from leafgreen/firered or from Pokemon colusseum.
You can't.
Evee can't be found on emerald so get one in firered or leafgreen then trade it to emerald.
I don't know,but it might be the same question as "where to find a eeve in Pokemon diamod
dragonite is the strongest dragon there is in leafgreen
You can't catch eevee as a wild pokemon, but you receive on the roof of the Celadon Mansion(you have to go through the back way, going through the front will take you the wrong way)
You can go to bebe and talk to her and she will give you an eeve.(Notebebe is in Hearthom city she will give you an eeve only if you have the national pokedex.
Evee is not availiable in Pokemon Sapphire.
I think its moltres
I guess Zapdos
at the end of the game
the best Pokemon are mewto and the rarest Pokemon ever mew.