Hmmm....my dream team would have to be.....
In blue version:
Iciclia(Articuno)
Electricia(Zapdos)
Flareia(Moltres)
Psychivia(Mewtwo)
Kittenfly(Mew)
Soleka(Venusaur)
That's the team I beat the Elite Four with my fourth time I fought them. I didn't even use Soleka, all I really needed were the 3 legendaries and that was it, because I mainly fought with them.
In Gold:
Fireblaze(Typhlosion)
Calypsera(Red Gyarados)
Marnie(Ho-Oh)
Apia(second Ho-Oh)
That's it. I nearly beat the Elite Four with them as well! I cloned Marnie, my original Ho-Oh and got Apia, still holding the Sacred Ash. But then I started a new game.
Haven't got one for Sapphire yet!