The Prophet (sal-Allaahu 'alayhe wa sallam) used to say between the Yemeni corner and the black stone:

رَبَّنَآ اٰتِنَا فِي الدُّنْيَا حَسَنَةً وَّفِي الْاٰخِرَةِ حَسَـنَةً وَّقِنَا عَذَابَ النَّارِ

Our Lord, grant us the good things in this world and the good things in the next life and save us from the punishment of the Fire.

Rabbanaa 'aatinaa fid-dunyaa hasanatan wa fil-'aakhirati hasanatan wa qinaa 'athaaban-naar.