I really like the font that is used in the editor window into which I am typing this right now - what is it?
The first one of those that's installed on your computer is the one you're seeing.
If you're on Windows Vista or 7, or have Office 2007 or Visual Studio 2010 installed, you'll have Consolas. If you're on a recent Mac, you'll be seeing Menlo or Monaco. You'll probably see one of the rest if you're on Linux.