Unless you mean "virtuoso pieces" only, you also could find suitable for your purpose those ones where the left hand carries the melody, for example, Chopin's Prelude Op 28 #6, and Etude Op 25 #7. Maybe also pieces having plentiful arpeggiatted accompanyment and simple -though intense- melodies, such as Rachmaninoff's Elegie, Field's Nocturne #14 in G, and Liszt's Consolation #3.