Concept: Route every egg Pokemon in Crystal (both the shiny and non-shiny versions, so 14 total). Shinies have DVs of 0/2/10/10/10 (HP Grass 50); non-shinies have 0/0/0/0/0 (HP Fighting 31) (lol). The Pokemon are: Pichu, Cleffa, Igglybuff, Tyrogue, Smoochum, Elekid, and Magby

Pichu: Thundershock/Charm/Dizzy Punch | Can learn Headbutt, Rollout and Mud-Slap
Cleffa: Pound/Charm/Dizzy Punch | Learns Sing | Can learn Headbutt, Rollout, Shadow Ball and Mud-Slap
Igglybuff: Sing/Charm/Dizzy Punch | Can learn Headbutt, Rollout, Shadow Ball and Mud-Slap
Tyrogue: Tackle/Dizzy Punch | Can learn Headbutt, Rock Smash and Mud-Slap
Smoochum: Pound/Lick/Dizzy Punch | Learns Powder Snow (L13) and Confusion (L21) | Can learn Ice Punch, Shadow Ball, Mud-Slap and Dynamicpunch 
Elekid: Quick Attack/Leer/Dizzy Punch | Learns Thunderpunch (L9 or TM), Light Screen (L17) | Can learn Ice Punch, Fire Punch, Headbutt and Dynamicpunch
Magby: Ember/Dizzy Punch | Can learn Fire Punch, Thunderpunch, Headbutt and Dynamicpunch

From fastest to slowest:
- Elekid
- Magby 
- Smoochum (huge gap after this)
- Tyrogue (evolve into Hitmonlee at L20)
- Igglybuff
- Cleffa
- Pichu (higher if you can evolve by L26 to learn Thunderbolt)