Guitar in my opinion. Such a beautifully versatile instrument. Pianos are amazing as well, but there’s something about strings that can convey even the slighest subtle dynamic. Not to mention the wall of sound that is also possible.
French horn! I love the full, mellow tones that it creates. One of the finest examples of its use in modern times is The Beatles’ “Sargent(spell?) Pepper’s Lonely Hearts Club Band.” In nearly every track on the album there are French horn parts.
I played the violin for years, so I have to say strings. I love the sound of the Banjo. Harmonica is nice too, but ONLY if the person really knows how to play it.
I’d have to say that my favorite instrument to listen to and play is Tenor Sax. I just think that it’s in the perfect octave. I like the alto too, but it’s still no match for the all-mighty Tenor!
Being an instrumental music teacher
I would say all musical instruments are beautiful, from the simplest to the more complex. That is when they are played well.
My favorite to play is definitly guitar but I love hearing other people sing! If that counts as an instrument, of course. If not, I’ve always had a thing for the piano ;)