oh thanks. but when should i start the nidoking thing? I could get a nidoran male from viridian city, but should i just get a nidorino from the safari zone like I did in red? Also, i'll just stick with charizard, because as i said, tradition. but what kind of flying type moves does he learn?
I've had Pokemon Yellow for roughly 20 years now and Nidoran is a solid early game choice for Brock since it learns Double Kick at level 12. Other options are Mankey(Low Kick at level 9) or getting a Butterfree for its Confusion and Status moves. Pikachu is a solid option for Misty but its possible to get Bulbasaur before you face her. For Lt.Surge, Sandshrew or Diglett are fine options. Any Fire or Flying type against Erica works wonders. Same deal for Koga. For Sabrina, simply overpower her with strong attacks(like Dig or Earthquake) or attacks that crit often(like Slash). Can also go with a Bug type like Parasect or a Psychic type with non-STAB moves(like Hypno Headbutt). Water/Ground types rule the day on Blaine and for the final Gym, Ground owns everything he has(with Psychic, Grass and Water as solid options).
Pikachu is a decent end-game option despite not being able to evolve(especially because it learns Thunderbolt naturally at 26) but if you want an idea as to what Eevee should evolve into, Jolteon is arguably its best Generation 1 form due to the fact you get Pin Missile(Bug type move). You get Eevee at level 25 and Jolteon doesn't know any Electric attacks should you evolve it right away and doesn't learn any until level 52 and Thunder. Hence the TM24(Thunderbolt) is recommended should you do this. It learns Pin Missile at level 36 and Thunder Wave at level 42.
For Grass types, I honestly find Bulbasaur to be the best and its hard to argue against it. The fact you get it relatively early(Cerulean) and around the same time you get Oddish and Bellsprout means you have options if you opt to not to go with it.
For Fire types, Charmander is acquired for free but I always had a soft spot for Vulpix(acquired at level 18 from Rocket Game Corner in Celadon). Charizard does gain Flying Type so the Fly HM would have STAB, hence that would be an upside for this dual-type Pokemon(just makes him vulnerable to Ice and Electric Attacks but immune to Ground moves(something that other Fire types lack)). Charizard does not learn any Flying moves so all Flying moves must be taught.
With regards to Water types, Squirtle is acquired after Vermilion Gym and hence is the earliest Water Type you can get. However, Lapras is arguably the best one to have due to its Type 2: Ice and naturally learning Ice Beam. Makes it perfect for Lance end-game and you acquire Lapras before Seel at Seafoam Islands.
I always have a Ground Type in my group since your rival will have Jolteon Saffron City onward if you win your first two battles. Diglett makes sense from a speed standpoint but I love Sandshrew and his raw power despite not learning any STAB moves naturally. I do not recommend NidoKing for this role because in Generation 1, Pin Missile does x2 Damage to Poison types(which Nidoran and its final evolved form happens to have). You'll want Onix, Geodude or a pure Ground type like Diglett or Sandshrew in this situation.
For a Psychic type, you get Abra or Drowzee around mid-game(Vermilion area), although its not necessary to be successful. Ground moves own Ghost Pokemon because they're part Poison, hence Bug Type moves are also effective. For Bug Types, Paras is really your only option unless you manage to get your hands on a Weedle somehow. Finally there is only one Ghost type(Ghastly and its evolved forms) and Dragon type(Dratini and its evolved forms). Ghosts are found in Lavender Town while Dratini is found in Safari Zone(fish with Super Rod).
Therefore for a Final Team, I typically have the following:
Electric type: Pikachu/Jolteon <- For Lorelai primarily, with a Fire Type to melt Jynx.
Fire type: Charizard/Ninetales <- If Charizard, also gain Flying type hence can handle Bruno Fighting types, else Ninetales for ideal matchups
Water type: Blastoise/Lapras <- Primarily for Surfing and Ice Type moves. Personal preference choice here
Ground type: Sandslash <- Owns Agatha Ghost's and Bruno's Rock Pokemon
Grass type: Venausaur <- Backup for Lorelai, Bruno and can handle Gyrados on Lance.
Flex pick: If you go with a pure Fire type, you'll want a Flying type for Bruno and for flying around). If Charizard is your option at Fire, then anything is possible: Parasect/Beedril(Bug), Hypno/Alakazam/Mew/Mewtwo(Psychic) or Dragonite(Dragon). Heck you could do Snorlax(too bad there's no pulverizing pancake).
