If you want to branch out to Spanish I went to Capote Y toros Friday night for tapas down Old Brompton Road - would recommend. Excellent food (though not quite up to Barrafina standards admittedly), buzzy atmosphere and a massive selection of sherries if that appeals.
Racine on Brompton Road gets a lot of good write ups for high end Bistrot food. They source their beef from O'Sheas I believe.
54 Frith St, London, Greater London W1D 3, GB