I started with Blue. Don't remember much.
Then Silver.
Then Sapphire.
Then Diamond.
are we seeing a trend?
My absolute favorite was Emerald. Behind that, pokemon Yellow (because pikachu followed you and stuff). But that's kind of silly, now, since in Soul Silver whatever pokemon is in slot 1 follows you around.
Favorite pokes:
Umbreon
Espeon
Eevee
Vulpix
Ninetales
Bellossom
Mightyena