Here are my top four monospace fonts displaying “In 100 years, Gates and Jobs will be forgotten, but Torvalds’ name will live on.”
I first noticed this font when looking at my friend’s printed Java code before a test. I had never seen such a nice-looking monospace font, since I usually work in Ubuntu Linux. I found out that she printed it out in Notepad++, and it was a Windows font named Consolas designed by Lucas de Groot. I prefer free fonts to proprietary (especially Windows) fonts, but Consolas looks the best.
2. DejaVu Sans Mono (‘Monospace’ font of Ubuntu 10.04 Terminal)
This is the default Terminal font of Ubuntu 10.04. It is listed as ‘Monospace’, but ‘Monospace’ is an alias for DejaVu Sans Mono. DejaVu fonts are free. It’s not as nice as Consolas, and the zero is dotted instead of slashed, but it looks very nice on the console.
Inspired by Consolas, Raph Levien designed the free font Inconsolata and released it under the SIL Open Font License. It has a slashed zero, and the dots of the i’s and the periods are circles instead of squares, but the font looks a bit vertically stretched.
4. Anonymous Pro
Anonymous Pro is another free font. The letters are aesthetically proportional and the zero is slashed, but it is a bit over-the-top with some overly serifed numbers and uppercase letters.
Dan Benjamin has a similar list in Top 10 Programming Fonts, if you want to see more favourably-reviewed monospaced fonts.