Route 3: Reward - Revive
Route 4: Reward - TM57 - Pay Day
Route 7: Reward - TM12 - Facade
Route 10: Reward - TM13 - Brick Break
Route 11: Reward - Pikachu Candy (LGP) / Eevee Candy (LGE)
Route 12: Reward - TM59 - Dream Eater
Route 15: Reward - TM31 - Fire Punch
Route 17: Reward - TM58 - Drill Run
Route 21: Reward - TM35 - Ice Punch
Route 25: Reward - TM15 - Seismic Toss
Cerulean City: Reward - TM60 - Megahorn
Celadon City: Reward - PP Max
Saffron City: Reward - TM23 - Thunder Punch
Pokémon Tower: Reward - Pikachu Candy (LGP) / Eevee Candy (LGE)
Power Plant: Reward - Rare Candy
Seafoam Islands: Reward - Rare Candy
Pokémon Mansion: Reward - TM22 - Rock Slide
Victory Road: Reward - Pikachu Candy (LGP) / Eevee Candy (LGE)
Victory Road: Reward - TM39 - Outrage
Source
Let me know if you need more detailed descriptions on how to find them.
