I have no input for you, but this is a niche I would love to get in to. The Open Government movement has made a ton of information accessible, but citizens aren't using it...I'd love to build apps in that space.
Music: something I don't know well so my brain doesn't want to try to sing...I usually put on a Pandora station for indie rock or metal
Keyboard: mechanical keyboard (blue switches...the noisier the better)
Monitor: 2 monitors...even though I only use one about 90% of the time, it's nice to have API docs, mockups, notes, etc. on the other one that are only a glance away. I prefer the monitors to be widescreen so I can put things side by side nicely.
Space: in my room, or if I have to be in an office, a desk far away from people with headphones on. There's also a 24/7 french bakery with awesome wifi that I did a majority of my college coding projects in...that atmosphere is naturally productive for me somehow lol
Always sitting. I have a standing/sitting desk at my work and I'm starting to take a liking to standing, but I feel less productive.
People surrounding: as minimal as possible unless we're group-thinking a problem