All just my personal opinion
Bach: Italian Concerto in F major, BWV 971 — Walter Gieseking (1940), Wanda Landowska (1933), Gustav Leonhardt (1965), Andreas Staier (1993), Ton Koopman (1986), Christophe Rousset (1990);
Bach: Partita in B minor, BWV 831, “French Overture” — Walter Gieseking (1950), Glenn Gould (1970), Christophe Rousset (1990), Andreas Staier (1993)
Bach: 4 Duets, BWV 802-805 — Ton Koopman, Christophe Rousset; Bach: Chromatic Fantasy & Fugue, BWV 903 — Wanda Landowska (1933), Andreas Staier (1988), Christophe Rousset (1990), Ton Koopman (1986)
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: 6 Bagatelles, op.126 — Ashkenazy (1984), Brautigam (2010), Brendel (1964 & 1985), Gould (1974), Schnabel (1937); Beethoven: 24 Variations on the Arietta “Venni Amore” by Vincenzo Righini, WoO 65 — Pletnev (1997), Brautigam (2012); Schubert: Symphony in B minor, D.759 (“Unfinished”) / Symphony in C major, D.944 (“Great C major”) — Furtwängler (1952), Harnoncourt (1992), Dausgaard (2006)
Jean-Philippe Rameau: “L’Orchestre de Louis XV”, Suites d’Orchestre — Le Concert des Nations, Jordi Savall; Domenico Scarlatti: Complete 555 Keyboard Sonatas — Pieter-Jan Belder
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)