Umbrella. And BR will win because this is a pop forum where people worship overrated songs that really had no real lasting effect in the real world, while GaGa fans will cling to it as it's arguably her largest song and "crowning achievement."
And didn't reach #1, an argument many of you use to validate whether or not a song was "iconic."
How many times have you heard "eh eh" repeated in songs since 2007? How many songs have you heard use "ra ra ah ah" since 2009? There you go.