consolas

Microsoft has released the Consolas font as a free download. Previously, this font was only available as a part of the Windows Vista preview versions. It's aimed primarily at programmers (and is technically only licensed for users of Visual Studio 2005), but it's also great as a general purpose monospaced font as well. If you're sick of looking at Courier New for all your monospace text, you owe it to yourself to go and download this font.