I play cello, classical guitar, and piano. Have an autoharp that I need to get new strings for (haven't learned to play it yet), and a trumpet that I'd love to learn, but it will upset my neighbours so I can't ever play it :-( And a valve is stuck, anyway.
Out of all of them I love my cello the best. But I hate the C-string, it's too low, I never play it. I'd love to get a viola one day, which is just a bit higher than the cello but not too annoyingly high pitched like the violin. It has its strings tuned in fifths like the cello, which is excellent, because when you figure out a tune, you can simply move up a string and play it with exactly the same fingering if you want to play it in a higher pitch. It just changes the key. As well as getting a viola one day, I'd love to find strings for a guitar that would let me have it tuned in fifths as well (without breaking the guitar or the strings), so I can do the same and move songs up and down without the relationship between the notes changing. Something I like about guitar is that it is in treble clef at least, so it's very easy to find new music to play. The cello is in bass clef so it's really hard to find sheet music for the songs I am looking for. Occasionally I find pieces written for solo bass guitar and can play those. I hardly play the piano anymore, because after learning guitar and cello it is almost boring. Press a button and get a perfect note? No thanks, too boring, too easy.