Note: This list only covers Gen 1, and will not cover special characters such as Gym Leaders, Elite 4, or your rival
Beauty: Bellsprout, Oddish, Exeggcute, Rattata, Pikachu, Vulpix, Clefairy, Meowth, Pidgeotto, Wigglytuff, Bulbasaur, Ivysaur, Poliwag, Goldeen, Seaking, Staryu, Horsea, Seadra, Shellder, Cloyster
Biker: Koffing, Weezing, Grimer, Muk, Voltorb
Bird Keeper: Pidgey, Pidgeotto, Spearow, Fearow, Doduo, Dodrio, Farfetch'd
Black Belt: Machop, Machoke, Mankey, Primeape, Hitmonlee, Hitmonchan
Bug Catcher: Caterpie, Metapod, Butterfree, Weedle, Kakuna, Beedrill, Venonat
Burglar: Charmander, Charmeleon, Vulpix, Ninetales, Growlithe, Ponyta
Channeler: Gastly, Haunter
Cooltrainer: Weepinbell, Gloom, Ivysaur, Nidorino, Nidoking, Sandslash, Dugtrio, Rhyhorn, Persian, Ninetales, Wartortle, Charmeleon, Charizard, Exeggutor, Cloyster, Arcanine, Parasect, Dewgong, Chansey, Kingler, Tentacruel, Blastoise, Bellsprout, Victreebel
Cue Ball: Machop, Machoke, Mankey, Primeape, Tentacool, Tentacruel
Engineer: Magnemite, Magneton
Fisherman: Magikarp, Goldeen, Tentacool, Staryu, Shellder, Poliwag, Horsea, Seaking, Cloyster
Gambler: Poliwag, Horsea, Bellsprout, Oddish, Growlithe, Vulpix, Voltorb, Magnemite, Poliwhirl
Gentleman: Growlithe, Nidoran(m), Nidoran(f), Pikachu, Ponyta
Hiker: Geodude, Onix, Machop, Graveler
Jr. Trainer: Diglett, Sandshrew, Mankey, Rattata, Ekans, Squirtle, Spearow, Raticate, Growlithe, Charmander, Nidoran(m), Nidorino, Weepinbell, Goldeen, Pikachu, Pidgey, Oddish, Bellsprout, Meowth, Clefairy, Bulbasaur, Ivysaur, Poliwag, Horsea, Pidgeotto, Raichu, Gloom, Tangela, Tentacool, Seel, Seaking, Cubone
Juggler: Kadabra, Drowzee, Hypno, Mr. Mime
Lass: Nidoran(f), Nidoran(m), Rattata, Pidgey, Jigglypuff, Clefairy, Oddish, Bellsprout, Pikachu, Meowth, Nidorina, Weepinbell, Gloom, Paras, Parasect
PokeManiac: Cubone, Slowpoke, Charmander, Rhyhorn, Charmeleon, Lickitung, Lapras
Psychic: Slowpoke, Slowbro, Mr. Mime, Kadabra
Rocker: Voltorb, Electrode, Magnemite
Sailor: Machop, Tentacool, Shellder, Horsea, Staryu, Pikachu, Magnemite
Scientist: Magnemite, Magneton, Voltorb, Electrode, Koffing, Weezing, Grimer, Muk
Super Nerd: Magnemite, Voltorb, Koffing, Grimer, Muk, Vulpix, Ninetales, Ponyta, Rapidash, Growlithe, Charmander
Swimmer: Horsea, Shellder, Staryu, Goldeen, Tentacool, Poliwag, Poliwhirl, Seaking, Tentacruel, Cloyster, Seadra, Starmie, Wartortle
Tamer: Arbok, Tauros, Sandslash, Rhyhorn, Persian, Golduck
Team Rocket Grunt: Sandshrew, Rattata, Zubat, Ekans, Raticate, Koffing, Meowth, Drowzee, Machop, Grimer, Sandslash, Arbok, Golbat, Weezing, Cubone, Hypno, Machoke, Marowak
Youngster: Rattata, Ekans, Spearow, Zubat, Slowpoke, Sandshrew, Nidoran(m), Nidorino, Raticate
Hope this helped!
