I was doing some routine poking around the TextMate Wiki tonight, and I came across an amazing mod. Amazing. After installing it, my favorite editor looked brand new, and I started hacking away at code for hours.
Customized (yet clean) interfaces really help me focus on my work. Working in an IDE with a black background just feels right to me. I wasn't nearly as satisfied with my .NET development when using the default Visual Studio color scheme. I found the dark and everything became better. I felt more at home. I looked at it and it made me smile.
Just a thought.