Of the hundreds of different moves in the Pokémon games, some are used exclusively by a single Pokémon or evolutionary lineup, known as that Pokémon's "signature move". Then, there's those other moves that are not officially "signature" because they are available to several different Pokémon, but are still commonly associated with a particular Pokémon. What moves that are not considered a "signature" move do you associate with a single Pokémon or evolution line? Even though Splash can be learned by Hoppip and a few other Pokémon since Generation II, I have always associated that move with Magikarp. Similar story with Hyper Fang and Rattata/Raticate. Conversely, even though Sand-Attack was never a single-Pokémon signature move, I have always associated it with Pidgey.
We can no longer say the Water Shuriken is Greninja's signature move, since Acelgor can learn it. Also, Kartana can learn Cut and Sacred Sword.
I agree with the magicarp splash. For some reason as a kid I thought only Pikachu could learn Thunder, mainly from the anime even though other Pokémon learned it too XD
I always thought Thundershock was Pikachu's signature move because Ash is always telling him to use it. And then I learned what signature moves actually were and realised I was wrong.
Talonflame and Brave Bird, anyone? I feel like Water Pulse should be Milotic's signature move. Also, when I see the word "Thunderpunch" I immediately think of Electivire.
I always thought of Horn Drill being a signature move of Rhydon, and Crabhammer for Kingler even though a bunch of later crab and lobster based Pokémon got it too. I also have to agree with those who think of Splash for Magikarp.
When I see Spiky Shield, I think of Chesnaught. But that's not really signature, because of Smeargle.
I thought the same thing back when I first started playing Pokémon! The one that comes to mind is Rock Wrecker for Rhyperior. Now that Dwebble and Crustle are in the mix, it's a sad, lost cause to make Rhyperior that much cooler.
I associate Metronome with Togepi, mainly due to the anime, even though many Pokémon can use it. Some others are Bone Club to the Cubone line and Aura Sphere to Lucario.