UPDATE: http://studiostyles.info/ for a great growing community of Visual Studio Styles and Themes. You can create, import and export themes in your browser!
More and more I find myself "skinning and themeing" my Visual Studio development environment in order to stay frosty. It's
surprising how changing your theme (fonts, colors, etc.) can
re-energize me when I'm having trouble with some problem or motivation.
Here's a gallery of some nice Visual Studio Themes to refresh your look.
Remember to always back up your settings so you can get back to the
way things were and have no fear when you're changing your settings.
Note also that some of these settings files you'll find out in the wild
may (mistakenly) have Keyboard Bindings included. You'll want to
selectively import just the fonts and colors that you want and avoid
importing over your own custom keyboard settings.
I switched to a darker scheme a while back, as have many others. I also spent a while looking for the perfect font as have others. When you stumble on a 2005 theme that you want ot use in 2008, Tomas has an XSLT to make the transition smoother.
Oren Ellenbogen's Dark Scheme
A lot of the darker schemes like Oren's don't use a True Black, but
an "off black." His theme is very low contrast and uses muted, relaxing
colors.
Mike "Blowmage" Moore's Ruby Blue
This is a low-contrast calm schema, but operators and numbers have a little "pop" to them.
Vibrant Borland by Mawi
This one bring backs good memories of writing Borland C++ with OWL
and Turbovision, with a little Norton Commander thrown in for fun.
CodingHorror
One of the few light-colored themes, Jeff's also uses a custom font
to make 0 and O stand out. Note that the white background is more of a
paper-colored off-white.
Dave Reed's Jedi Scheme
Dave's schema uses a complete black, and a neon blue. A little intense, but much higher contrast.
Damien Guard's Humane
This earthy theme includes little details like smart fonts and italics.
Tomas Restrepo's Themes
Tomas has done a huge amount of work in this space. You can get seven of his themes here. He's even got a tool to port color schemes from Visual Studio to SQL Management Studio.
Desert Nights
This theme uses the greatest range of colors outside of the Vibrant
Ink them, and approaches, but doesn't reach, a number of primary colors.
Garden of Eden
Green, Kermit-green, sea-green, they are all here in this blue-green theme.
Ragnarok
Initially similar to many dark themes, this one uses complementary
colors to provide contrast between identifiers and keywords, string
literals and comments.
Nightingale
A more cheerful dark theme that includes italics for string literals and brighter neons for keywords.
Moria Alternate
This uses Deja Vu Sans Mono as it's font and uses a lot more neutrals and grays outside of the keyword space.
Brad Wilson Dark Visual Studio
A muted, low-contrast theme with blues and purples. Even the yellow is relaxed.
Martin Plante (slimCODE)
Martin likes small text, no ClearType to take advantage of crisp LCD
screens. Rather than committing to blue or black he goes for a
navy-gray-blue background.
John Lam's Vibrant Ink Port
John's trying for a straight port of Textmate's famous Vibrant Ink.
This is a sharp, bright, neo-classic theme. Note his use of Monaco.
Rob Conery - Textmate
This is Rob's take on Vibrant Ink, added Consolas as the font, some bolding, and lowers the contrast a smidge.
http://www.hanselman.com/blog/VisualStudioProgrammerThemesGallery.aspx