All just my personal opinion
Felix Mendelssohn Bartholdy: Songs without Words (Lieder ohne Worte) played by Ilse von Alpenheim, in her complete recording from 1980 — there’s more to this than mere encores! Also included are two interesting sets of variations (opp.82 & 83), and the Andante cantabile e presto agitato in B major
Schumann: Liederkreis op.39, Dichterliebe op.48 — comparing recordings with the following artists: Fischer-Dieskau/Moore (Live, 1956), Fischer-Dieskau/Brendel (1986), Goerne/Schneider (1998), Terfel/Martineau (1999), Wunderlich/Giesen (1965), Bostridge/Drake (1997); notes about related recordings
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