I've just upgraded to a new 13" Retina MacBook Pro and I still can't get over how good the screen is. At work, it's hooked up to two external displays as well: a 30" Dell UltraSharp, which can comfortably fit several full size browser windows adjacent to each other, and an LG 24" widescreen that I've rotated to be vertically orientated: this makes an excellent coding window. A pair of high-quality AKG K240 headphones are often clamped to my head.
A good quality A4 notepad and fine gel pen are never far from my hands as well. Almost all of the FastMail UI starts life on paper first, where I can quickly sketch and play with ideas before moving on to code.
When I start my day, I automatically fire up Sublime Text, a terminal or two (for git and ssh to our servers) and pretty much all of the major browsers (but mainly Opera or Chrome for developing; the Chromium dev tools are currently the best IMO). Spotify provides the tunes, and I turn to Acorn if I need to do some light image editing. I use The Hit List to track my tasks and projects and Adium for trolling our staff IRC channel. The excellent Kaleidoscope handles my diffing needs and I'll open up other browsers as needed for testing. I obviously access my mail through the FastMail web interface.
Pretty much what I have now! High-density desktop displays are finally starting to appear on the market, so I'm sure I'll be lusting after one (or two!) of them soon, but I'm pretty happy with my setup at the moment.
Constant curiosity with what else is happening in the world, both in our industry and outside it, combined with a critical and analytical viewpoint.