All just my personal opinion
Lieder recordings (Beethoven & Schumann) with Fischer-Dieskau/Moore, Wunderlich/Giesen, Goerne/Schneider, Terfel/Martineau, Bostridge/Drake; Schumann: Piano Quintet op.44, Piano Quartet op.47 — Melnikov/Jerusalem Quartet, Levine/LaSalle Quartet; Webern: 6 Bagatellen, 5 Movements for string quartet, op.5 — Hagen Quartett
Domenico Scarlatti: Keyboard Sonatas — recordings with Pieter-Jan Belder and Andreas Staier; Schubert: Masses in A♭ (D.678) and E♭ (D.950) — Nikolaus Harnoncourt, Chamber Orchestra of Europe, Arnold Schoenberg Choir
Beethoven, 12 Variations on “Das Waldmädchen”, WoO 71 — comparing recordings with the following artists: Emil Gilels (1968), Vladimir Ashkenazy (2006), Olli Mustonen (1993), Ronald Brautigam (2010)