Alrighty then, let's give this one a shot. The first Pokemon listed is the one with the signature move originally, and the second is the first one to receive it (By level up, preferably, but if none learn it through level up then the second listed Pokemon gets it through breeding.) And not by events either.
Gen 1
- Frenzy Plant (Venusaur to Meganium)
- Blast Burn (Charizard to Typhlosion)
- Hydro Cannon (Blastoise to Feraligatr)
- Twineedle (Beedrill to Escavalier)
- Rolling Kick (Hitmonlee to Hitmontop)
- Hi Jump Kick (Hitmonlee to Hitmontop)
- Dizzy Punch (Kangaskan to Spinda)
Gen 2
- Megahorn (Heracross to Nidoking)
- Extreme Speed (Arcanine to Rayquaza)
- Mach Punch (Hitmonchan to Hitmontop)
- Morning Sun (Espeon to Solrock)
- Pain Split (Misdreavus to Mismagius)
- Beat Up (Sneasel to Weavile)
- Octazooka (Octillery to Grapploct)
- Mimic (Suduwoodo to Jigglypuff)
- Sacred Fire (Ho-Oh to Entei)
- Present (Delibird to Chansey)
Gen 3
- Signal Beam (Volbeat to Dewgong)
- Slack Off (Slaking to Slowpoke)
- Teeter Dance (Spinda to Lilligant)
- Assist (Skitty to Glameow)
- Grasswhistle (Roselia to Sunkern)
- Poison Tail (Seviper to Venipede)
- Weather Ball (Castform to Lugia/Ho-oh)
- Blaze Kick (Blaziken to Hitmonlee)
Note: Leaf Blade and Muddy Water are not here because they are learned by Grovyle and Marshtomp, not just Sceptile and Swampert.
Gen 4
- Rock Wrecker (Rhyperior to Dwebble)
- Heart Swap (Manaphy to Magearna)
(Wow, is that really it? It's all I can find.)
Gen 5
- Horn Leech (Sawsbuck to Phantump)
- Night Daze (Zoroark to Lunala)
- Secret Power (Audino to Vulpix)
(That's really it and one of them was an example?)
Gen 6
- Water Shuriken (Greninja to Accelgor)
- Crafty Shield (Klefki to Chimecho)
- Spiky Shield (Chesnaught to Cacturne)
- Mystical Fire (Delphox to Mismagius)
- Powder (Vivillion to Cutifly/Ribombee)
- Flying Press (Hawlucha to Pikachu-Libero)
Gen 7
- Throat Chop (Incineroar to Obstagoon)
- Darkest Lariat (Incineroar to TR)
- First Impression (Golisopod to Galarian Sirfetch'd)
- Psychic Fangs (Bruxish to TR)
- Zing Zap (Togedemaru to Pincurchin)
- Sparkling Aria (Primarina to Lapras)
- Fire Lash (Heatmor to Centiskorch/Salazzle)
Gen 8
Gen 9 has not been released as of writing this, so I'll list all the signature moves of Gen 8.
- Surging Strikes (Rapid Strike Urshifu)
- Wicked Blow (Single Strike Urshifu)
- Eternabeam / Dynamax Cannon (Eternatus)
- Behemoth Bash-Zamazenta (Crowned Shield)
- Behemoth Blade-Zacian (Crowned Sword)
- Glacial Lance (Calyrex-Ice Rider / Glastrier)
- Astral Barrage (Calyrex-Shadow Rider / Spectrier)
- Thunder Cage (Regieleki)
- Dragon Energy (Regidrago)
- Freezing Glare (Galarian Articuno)
- Thunderous Kick (Galarian Zapdos)
- Fiery Wrath (Galarian Moltres)
- Dragon Darts (Dragapult line)
- Snipe Shot (Inteleon)
- Pyro Ball (Cinderace)
- Drum Beating (Rillaboom)
- G-Max Hydrosnipe (Inteleon)
- G-Max Fireball (Cinderace)
- G-Max Drum Solo (Rillaboom)
- Fishous Rend (Dracovish / Arctovish)
- Bolt Beak (Arctozolt / Dracozolt)
- Aura Wheel (Morpeko)
- No Retreat (Falinks)
- Decorate (Alcremie)
- Spirit Break (Grimmsnarl)
- Octolock (Grapploct)
- Overdrive (Toxtricity)
- Apple Acid (Appletun)
- Grav Apple (Flapple)
- Tar Shot (Coalossal)
- Jaw Lock (Drednaw)
- Meteor Assault (Sirfetch'd)
- G-Max Replenish (Snorlax)
- G-Max Malodor (Garbodor)
- G-Max Wind Rage (Corviknight)
- G-Max Finale (Alcremie)
- G-Max Gravitas (Orbeetle)
- G-Max Stonesurge (Drednaw)
- G-Max Volcalith (Coalossal)
- G-Max Sweetness (Appletun)
- G-Max Tartness (Flapple)
- G-Max Sandblast (Sandaconda)
- G-Max Steelsurge (Copperajah)
- G-Max Depletion (Duraludon)
- G-Max Cuddle (Eevee)
- G-Max Volt Crash (Pikachu)
- G-Max Befuddle (Butterfree)
- G-Max Gold Rush (Meowth)
- G-Max Chi Strike (Machamp)
- G-Max Terror (Gengar)
- G-Max Stun Shock (Toxtricity)
- G-Max Meltdown (Melmetal)
- G-Max Centiferno (Centiskorch)
- G-Max Snooze (Grimmsnarl)
- G-Max Smite (Hatterene)
- G-Max Foam Burst (Kingler)
- G-Max Resonance (Lapras)
- G-Max Rapid Flow (Urshifu-Rapid Strike)
- G-Max One Blow (Urshifu-Single Strike)
- G-Max Wildfire (Charizard)
- G-Max Vine Lash (Venusaur)
- G-Max Cannonade (Blastoise)
If I missed anything, please let me know. And remember that he said ONE POKEMON, not one evolutionary line.