I do a lot of demos: training, teaching, mentoring, etc. I get asked about my Visual Studio fonts and colors quite often. I use Tomas Restrepo's Nightingale scheme for Visual Studio 2008. Here's the link to his VS Color Scheme page. Scroll down to check out Nightingale and other nice schemes he's made available. I like the contrast of Nightingale and how colorful it is. I use a different font though called DejaVuSans Mono. It's clean and compact yet bold.

Here's a screen shot of the Nightingale theme with the DejaVuSans Mono font that I use. By the way, setting the vertical guidelines that you see in the image below is done through a registry hack. See the REG script below if you're interested.

Save the text below as a REG file, then right-click on the file and select Merge to update Visual Studio 2008 to show gridlines at positions 4, 8 and 80. Of course, if you want vertical guides at other positions, change the Guides string to your liking. Visual Studio 2005 respects this setting, too. Just change 9.0 to 8.0 in the path. Here's the REG merge script: