Beautiful Classical Smaller Pieces, duo,trio,etc

The Brahms Clarinet Quintet should be added to the list.

Schubert's Cello Quintet of course.

Of the top of my head;
Brahms Sextet No. 2 in G Major, Op. 36 (Sextet for Strings)
Beethoven's String Trios

The four albums in the Miracle series from KKV.no featuring Aage Kvalbein on Cello are magnificent. Two of them are also available on vinyl Itallian and Spanish Miracles. Highly recommended and available at KKV.no search Kvalbein

Good listening

Peter

Neo classical quartets:
Kronos
Balanescu;

Tango: Quintet Buenos Aries

The Julian (Bream) and John (Williams) guitar duo albums are great (Assad Bros. duo also excellent).
Violin/Piano: I like the Prokofiev Sonata #2 (originally flute) and the Saint-Saens Sonata #1.
String Quartets: Debussy or Ravel (Guarneri has a fairly recent high-quality LP of the Ravel w/two movements per side).
String Quintet: Schubert Quintet in C--give me heaven before I die