In no particular order.
Martha Argerich
Maurizio Pollini
Evgeny Kissin
Emil Gilels
Mitsuko Uchida
Daniil Trifonov
Yuja Wang
And others...
I do hold a special place for Ursula Oppens. Of course, her playing is great, but I love that she has always been a champion for modern and contemporary classical music; Carter, Charles Wuorinen, Stefan Wolpe, Joseph Schwantner, Joan Tower, etc.
For example, her performance of Carter's Piano Concerto, is world class. And it is not exactly an easy piece to play.