Richter probably has to be mentioned.
Also, of the "younger" pianists, I would say Hamelin has a great technique.
You did not go to hear Horowitz in order to hear a note perfect performance. You went to experience the sound that he could get out of the piano, and to have your hair standing on end for a good while after the recital. When I heard Horowitz play, he began with a set of Scarlatti, then Beethoven op. 101, the second half was all Chopin - some mazurkas, a nocturne, Polonaise, Scherzo #1, and Ballade #4. There were a few wrong notes in his unbelievable performance of the Chopin. The Scarlatti was very clean, and the op. 101 was as well.