The Best Signature Move Swaps in Pokémon History!

Any Pokémon would be lucky to receive a Signature Attack of some kind so that they could use a move that no one else can, however every so often when the stars align a move made for one Pokémon can find itself exclusive on a Different Pokémon years later! And what's really strange is that it's happened enough to make a whole list, so let's see the Best Signature Moves that have been transferred to new Pokémon over the generations!