GaGa >>>>> Adele had impact but not nearly as much. Even though music was already moving towards a dancier/futuristic sound, along with look, GaGa pushed it into the mainstream far faster than it would have done naturally.
Adele categorically would not have smashed as hard as she did had pop music not become so gimmick-y and theatrical. People loved that she represented the antithesis of all that, so I say Stefani who helped propel pop culture into that state
