Windows/Mac/Linux: If you've ever hacked around in your computer's terminal or command prompt, you've had moments where there's way too much text to fit on your screen. ProFont, made especially for terminals and programming, is meant to be tiny, so you can read lots of data all at once.
Coders are more than a little particular about their comfortable setup, so ProFont may not be a new default setting in editors of choice. But for those want to give it a go, or for casual users who'd like something that's very readable at any size, ProFont is a nifty little font that lets you fit more text onto a screen and scan it for what you're looking for. I learned about ProFont from a programmer who said it was his first post-installation step on any Mac he uses, and I've found a small but dedicated set of fans for ProFont on the web.
ProFont for Windows, for Macintosh, for Linux [Tobias Jung