In order of descending skill level:
I mainly play percussion instruments. Battery, percussion "toys", SFX, mallets, miscellaneous membranophones, you name it. I first started with the piano, but it was too hard to teach it to myself, so went to something simpler: battery percussion and toys/SFX. After I mastered all 40 rudiments, I started to lean towards mallet percussion. Now, I almost always play either marimba, vibraphone, timpani, or toys/SFX.
I also play the bassoon. This instrument was the hardest instrument I've tried to play. It took me a looooong time before I got comfortable with it. I almost gave up on it, but its sound was too beautiful to give up. I don't have my own bassoon though, because each one costs way too much.
Then there's the bass guitar. I just love bass instruments. I played a regular guitar at first, but I just didn't like it that much. So, I switched to bass guitar.
I've played alto, tenor, and bari sax at a decent level. I eventually stuck with alto sax because my older brother plays tenor and my younger brother plays bari.
I started flute for a few months, but my younger brother soared way past my level so I got discouraged. I also play trumpet and trombone (mostly trombone) when I have to fill in for someone who's absent, usually second chair. And of all the wind instruments in a concert band, I've never tried clarinet. I've always wanted to take cello, but never really got around to it.
Everything listed, with the exception of drum rudiments, was self-taught.