I like my desktop to be bright and stimulating. I love a certain kind of blueish gray (or grayish blue as you like). The RGBs are #6B73A9.
I also like the aluminium decoration of the mac. It's clear, its clean and it does not distract from the task at hand. So probably brushed metal look will be nice.
I am not one to have a wild wallpaper desktop image. I prefer calm and quite abstract patterns. I get a kick out of mathematically motivated images.
Lets translate this into requirements:
- Windows are white or very light gray
- Borders are medium gray
- Menus and tool bars are same medium gray
- No separation lines between window title, menu bar and tool bars
- Windows in the background are darker than windows in the front
- Selections are my favorite gray-blue
- Information windows, tool tips and hints are a faint yellow
- Text is dark gray, not black (black is to hard on the eye)
- Window corners are rounded
- Tabs and panels should look like they are extruded a bit
- Firefox and Thunderbird have corresponding themes
- Icons are more photo realistic (however, harddrives do not have to look like the naked bare metal)
- Prefer XML definition to images (slower loading)
I also consider positioning the window buttons (max, min, close) on the top left side. This minimizes the way, you have to move the mouse.