1. Grand Piano
2. 6-8 string acoustic or electric guitar (even though it's overrated as fuck and guitarists are a dime a dozen it's still a very essential and versatile instrument)
3. Acoustic drum kit (most fun to play, helps keeps all music in time like a metronome)
4. Keyboard (most verstile instrument, can mimic all other instruments)
5. Harpsichord
6. Cello (best of all stringed symphonic instruments)
7. Saxophone (I don't generally like it, but when played by a talented jazz player it sounds great e.g.
https://www.youtube.com/watch?v=WmWJPJUdPkA)
900000000001.Congas
9000000000000000000001. Tamborine
9000000000000000000000000000001. Ukele