OTF Ghostscript Fonts
Ghostscript is a free software suite that provides libraries to help your computer explain your printer how you would like things to show up on a piece of paper. Somewhere along it's development, a typography company called URW++ decided to contribute a sizable pack of fonts to the project. The group of fonts is very nice because it includes near-replicas of typefaces like Helvetica (Nimbus Sans L) but, unlike Helvetica, is free. Unfortunately, it looks like not very many people have taken interest in the collection so it hasn't been distributed much outside of Linux distributions.
I am currently stuck on a Windows machine so I don't have easy access to these fonts. In my rummaging around the internet I couldn't find any copies of the typefaces in a format that would install on Windows so I decided to make some. I took copies of the fonts from a Linux distribution and converted them to OTF. Here is the resulting font pack:
The tarball contains the following families:
URW Century Schoolbook
URW Nimbus (Sans, Mono, and Roman)
Because they are all in OTF, they can be installed on Windows. They may look a little wonky in your word processor but that is most probably because of a rendering issue; if you are super anal-retentive and want to be sure, convert your document to a PDF or SVG and examine the font in that format before printing.