If you fancy breaking out of the Times–Helvetica (or Times–Arial) mold, you might want to take a look at this PDF that displays usable text fonts (not the decorative stuff) and links to the websites from which each is downloadable. All the fonts will work on Linux, Microsoft and the latest Apple machines and are offered gratis by their creators; many of them are also libre, but some are restricted by licence.
The PDF guide to free fonts is available from http://www.garzo.co.uk/documents/freefonts.pdf.