depends on the game.
Firered: Charizard
Snorlax
Articuno (no im usually not an uber user, but Articuno is my fav, and it's a minor legendary)
Lapras
Nidoking
Raichu
(i didnt start naming my pokemon until platinum, so)
Soulsilver: Scyther (dumped my croconaw for one, but forgot to evolve it. It was so boss, I beat the whole elite four with only it. Either that, or I just forgot the other pokemon)
Emerald: Blaziken
Crawdaunt
Flygon
Mightyena
Manectric
Crobat
Diamond: Torterra
Gabite (didn't get to finish game, but it was beast)
Staraptor
Pearl: Infernape
Staraptor
Floatzel
Roserade
(rest i forgot)
Platinum: Terrace the Torterra
Sora the Milotic
Jack(al) the Lucario
Howler the Houndoom
Raptor the Salamence
Garuda the Blaziken
White: Samurott
Sigilyph
Musharna
Cofagrigus
Scrafty
Excadrill
Im thinking of importing six of my best pokemon to my white.
Which would be: Charizard (favorite pokemon)
Jack
Sora
Garuda
Articuno