For me its headphones unless I like what is playing in the shop (we have speakers in FAI connected to the shop speakers with our own volume control. I like hard rock/metal (Disturbed, Korn, Volbeat, Slipknot, ect...)
I work in a warehouse so headphones are a no-go for us since we have material handling equipment all over the place.
I have a small altec lansing speaker on my desk that i keep at a pretty low volume.
I also listen to mostly metal so i try to limit my music to instrumental as to not offend anyone. there are some pretty complaint happy people in my immediate vicinity.
I wear Bose Quiet Comfort 35 ii and I'm listening to 'Stab' by 'Built to Spill'. Been wearing these for about 1.5yrs now and worth every penny! 3 other engineers wear them here in the same office... we look like we're sponsored by them hehehe.
Edit:
I am subscribed to Amazon music (step up from Prime subscription). I've tried a few music boxes and I like this one the most.
AKG earbuds, my wife just got a new Samsung. Best wired earbuds available, though she's started to listen to more music on her phone, so I gotta give them back. Still have an older pair, though, and some true wireless buds (going to a no jack phone in October, better get used to them).
I listen to too much psych/stoner music, today was Kikagaku Moyo, Psychedelic Porn Crumpets, and a new Spotify weekly sampler that was actually pretty good this week, lots of new stuff.
Metalheads, try the New King Gizzard album, Infest the Rat's Nest, and a band called Petyr, a bit harder than the stoner crap I normally listen to but pretty good.