I guess there are not too many classical music lovers.
But here goes: Schubert's last three string quartets, his
violin sonatas, piano trios, string trios, string quintet.
Brahms viola sonatas, piano quartets and piano concertos. Beethoven string quartets, and his piano trios. All of Webern's instrumental works. Dvorak's string quartets. Mozart's 40th symphony and his piano concertos. Those are the ones that I can listen to over and over. Tons of others
from Schumann/Mendelsohnn/Berg. I loved Bruckner in my
youth but I oded on him.