Pokémon Gold / Silver

Special Features

-Now able to catch up to 250 Pokémon, excluding the old Legendary Birds, Mewtwo, and Mew
-Better color sequence than Yellow
-Better organized pack than R/B/Y with pockets for TM's, Pokeballs, items, and special items.
-Able to battle both the Johto and Kanto gym leaders
-2 new HM's, Whirlpool and Waterfall
-Attacks changed somewhat.  Bite becomes dark.  Fire Spin doesn't prevent attacks anymore.
-Magnemite/Magneton gain the Steel Type
-New Pokegear allows you to call important people, use your map, the new feature of a radio, and to check time.
-New ability to hold items to change the tide of battles or evolve certain Pokémon.
-Friendship evolutions for Eevee, Chancey, and Golbat along with others.
-Move Deleter able to delete HM moves and other moves as well.
-Different color schemes for Pokémon, known as shining Pokémon.

Pokémon not in Gold
-Articuno
-Zapdos
-Moltres
-Squirtle
-Wartortle
-Blastoise
-Charmander
-Charmeleon
-Charizard
-Bulbasaur
-Ivysaur
-Venusaur
-Delibird
-Phanpy
-Donphan
-Kabuto
-Kabutops
-Omanite
-Omastar
-Ledyba
-Ledian
-Mew
-Mewtwo
-Celebii
-Vulpix
-Nintails
-Meouth
-Persian
-Skarmory

Pokémon not in Silver
-Growlithe
-Arkanine
-Spinarak
-Ariados
-Articuno
-Zapdos
-Moltres
-Squirtle
-Wartortle
-Blastoise
-Charmander
-Charmeleon
-Charizard
-Bulbasaur
-Ivysaur
-Venusaur
-Gligar
-Kabuto
-Kabutops
-Omanite
-Omastar
-Mankey
-Primeape
-Mantine
-Mew
-Mewtwo
-Celebii
-Tediursa
-Ursaring