If you write code (HTML, XHTML, CSS, JS, PHP, etc.), then the Anonymous Pro monospaced font may be of some interest to you. It’s intended for coders and developers/designers (the 0, of course, is crossed;-) and it includes Cyrillic characters.

You can download it for free from here:

www.ms-studio.com/FontSales/anonymouspro.html

But my personal preference for a monospaced font is Consolas. As far as I know, this new font by Microsoft can be downloaded for free, too; Consolas is readable and suitable for all kinds of code — in my case, I most often see XHTML and CSS code blocks in it:)