When designing a page, one of the issues that should always be considered is what font is specified for body text, headings, and other HTML elements. Unless you use specialized font embedding techniques, the best you can do is figure our which fonts have the greatest saturation on the major computing platforms and order the font-family specification accordingly. You don’t want to use only one font name, because there are differences between the “standard” fonts in Windows, Mac OS X, Linux, and mobile systems. In addition, the very basic serif, sans-serif, monospaced, fantasy, or cursive should always be the final fallback, because the official HTML specifications demand that any browser implement a means of rendering those. What font is actually chosen for those rules is platform dependent, and may be ignored when using text only browsers that have very limited means of modifying the rendered information.
In the spirit of Spring Cleaning, I recommend an article that provides the very latest word in font stacks, including screen shots of platforms and browsers: