Nearly anything from the Safari Zone is strong as fuck.
Jolteon is top tier, but you have to give it Thunderbolt.
Starmie, Cloyster, Gyarados, Vaporeon, Omastar, and Lapras are fantastic Water-types.
Victreebel & Venusaur destroy the game with Razor Leaf.
Same with Persian using Slash.
Any Psychic will do well, even shit like Mr.Mime.
Rhydon is the best Rock or Ground type, but it needs TMs to be good. Dugtrio is acceptable if you don't want to use TMs. Don't forget gen 1 Dig has 100 power.
