Beautiful Classical Smaller Pieces, duo,trio,etc

I like "The Complete Mozart Divertimentos" NY Philomusica records, Disk 2.
I was driving home late, after a brutal day at work, and heard a track on the radio.
It was so beautiful and otherworldly that I felt like time stopped and I was dreaming.

The mendhelson octet!

All of the Baroque titles on the Harmonia Mundi label, if you find period instruments "beautiful".

The Mozart Flute/Harp Concerto. Mozart clarinet concerto. Mozart also wrote a lot of chamber music for winds. I have always been struck by how beautiful and ingenious Mozart's writing for winds is. His Grand Partita is one of his most famous works for winds. In this piece he uses the Bassett Horn. Its timbre is similar to the clarinet's, but darker and has an extended lower range.

Beethoven's string quartets. Bartok's string quartets. Mozart's string quintets. Brahms string sextets are things of beauty.