1) Quiet (but not isolated; 'Net and phone are adequate in this regard).
2) Clean (allergies).
3) Some natural light.
4) Ability to make basic ergonomic adjustments. Also the ability to get up and move around immediately and at will (helps my health, concentration, and to settle restlessness).
And, probably more in line with the question's expected responses:
5) Adequate (doesn't have to be exceptional) equipment and screen real estate.
Pretty simple. Yet I've found them ridiculously difficult to come by. People seem to really appreciate my work, yet they cannot seem to grasp the concept of allowing me these basic controls over my environment.
This is a primary motivation for my shifting to self-employment. Wish me luck.
EDIT: Currently, the home office has an L-shaped desk composed of two 6 ft x 2.5 ft segments with the height and angle of each segment independently adjustable. This provides plenty of workspace; I still find physical writing, printouts, and layout/organization of items useful in organizing my work and thoughts.
Windows on both sides, but now with the blinds closed due to a recent burglary :-( . Laptop with a separate keyboard. There was a second laptop, but it was ripped off. I don't have a particular need for a desktop; laptops have enough processing power, have effectively a built in UPS, and can travel with me. Short term, I'm substituting an older desktop for the stolen laptop. Some backup drives, printer, whatnot.
CFL desk lamp (soft white) and torchiere (daylight). Also a high intensity full spectrum "light box" angled to bounce off the white ceiling (otherwise, the LCD screens get washed out). The daylight / full spectrum bulbs do make a difference in perception. But they do not match the quality of and circadian synchronization provided by natural lighting.
