.............those of the beautiful Asumpta Serna in the 1986 film Matador by Pedro Almodavar...they must be at least one and a half inches long and hard as granite.
But running a very close runner up must be those of Kathleen Turner in Crimes of Passion with Anthony Perkins.
Then of course there are Dirk Bogarts nips in the wonderful The Night Porter, as the stunning Charlotte Ramplin sucks them and fucks him.
Of course if any of you wonderful people here on SH have better suggestion, please speak, better still if you care to share your own, then please post - I'm sure everyone would love to view.