Guitar, bass, drums, keyboards, are what I'm confident in. I play well enough on all of them to sit itn at any jam, and try to compose on all of them. I also pick banjo, dobro, pedal steel, and mandolin, but I really just don't enjoy them enough to put in the effort to get proficient.
I play Piano and Keyboards - I can play Clementi Sonatas and bits of Mozart and Haydn Sonatas (though I'm not as good as most piano students who are working that stuff up for recitals)
I play Guitar and Bass, though my hands are small so Bass isn't something I play with any regularity.
I play Mandolin as good as Billy Joe Armstrong plays Guitar (maybe better).
I can play a little of some other stringed instruments, but mainly just messing around - Banjo (very limited), Appalachian Dulcimer (somewhat limited), Hammered Dulcimer (OK), and Violin/Fiddle (poorly).
I can also play Harmonica a little - enough to get through Piano Man and What I Like About You at a gig. I can also play Recorder a bit - better than your average 5th grader playing those plastic ones - but not by much
Since computer is now an instrument, I play that too.
I wish I could play some winds - Flute, Sax, Trumpet - something to work on in the future.
I also played percussion throughout school, and focused mainly on mallet percussion (since I was usually the only drummer who could read pitch from my piano studies) but I was never very good at snare drum rudiments and that sort of thing. Can sit behind a kit and play a basic beat, but I don't consider myself "able to play drums" in any useful manner. Percussion, yes, Drums, no.
guitars have been the mainstay for almost 25 years, but I've dabbled (sometimes extensively) in a wide variety of other stuff, from the comparatively easy (mandolin, folk harp) to the blindingly difficult (shakuhachi, sitar.)
I've played Native American flute for about 15 years. Like a recorder, it's easy to play, but hard to play well. I probably play flute as well or better than I do guitar.
I also play transverse bamboo flute.
And now, with the help of my trusty loopers, I can do it all!