All just my personal opinion
Comparing recordings with the following artists: Wilhelm Backhaus (1966), Paul Badura-Skoda (1969), Daniel Barenboim (1984), Ronald Brautigam (2008), Emil Gilels (1985), Friedrich Gulda (1967), Igor Levit (2013), Maurizio Pollini (1976), Svjatoslav Richter (1965), Artur Schnabel (1935)
Beethoven: Piano Sonatas — summary for comparisons of recordings, involving the following artists: Wilhelm Backhaus, Paul Badura-Skoda, Daniel Barenboim, Ronald Brautigam, Edwin Fischer, Emil Gilels, Friedrich Gulda, Clara Haskil, Jos van Immerseel, Julius Katchen, Wilhelm Kempff, Igor Levit, Mikhail Pletnev, Maurizio Pollini, Svjatoslav Richter, Arthur Rubinstein, András Schiff, Artur Schnabel, Mélodie Zhao
Beethoven, “Eroica”-Variations op.35, Comparing recordings with the following artists: Artur Schnabel (1938), Glenn Gould (1970), Svjatoslav Richter (1970), Emil Gilels (1980), Konstantin Scherbakov (1984), Alfred Brendel (1985), Olli Mustonen (1993), Ronald Brautigam (2010)
Schumann: Novelletten, op.21 — Richter; Myaskovsky: Cello Sonata Nr.1 in D, op.12 — Mørk/Thibaudet; Rachmaninoff: Vocalise from the 14 Songs, op.34 — Isserlis/Hough; Rachmaninoff: Cello Sonata in G minor, op.19 — Mørk/Thibaudet, Isserlis/Hough; Franck: Violin or Cello Sonata in A — Spivakov/Bezrodnyi, Perlman/Argerich, Isserlis/Hough