As for my favorite instrument, I actually have two piano and violin both can describe and express feelings, harmony and melody.
I'm a big fan of Samvel Yervinyan,
whenever he's with Yanni, no words needed.
The suona is another contender for the sound of human suffering. I've always loved it.
https://www.youtube.com/watch?v=ki4dAB4SlMc (0:02-0:16; 1:30-2:10)
It's very relaxing.