For HGSS
(list includes Pokewalker pokemon excluding event Pokewalker pokemon. List consist of Pokemon Pre-National Dex)

>Top Tier
>Pokemon consist of Pokemon that from the moment you get them are extremely useful have have very small if any issues in game. They usually have very high stats, a great typing, great ability sometimes found relatively early, a great movepool or a combination of the above. You can't go wrong with choosing these pokemon

Typlosion family
Feraligatr family
Golem family
Quagsire family
Nidoran family
Scyther family
Heracross
Magneton Family
Azumarill family
Tauros
Miltank
Magmar family (Pokewalker)
Jynx family (Pokewalker)
Electabuzz family (Pokewalker)
Tentacruel family
Lanturn family
Gyarados
Kingdra family