In a previous life one of my main functions was publication design; fonts are important to me.
There are two font families that I usually install on all my systems:
- For maximum legibility, Lexend.
If the reading speed of your users is more important to you than fashion statements, this family is worth considering. It's the result of many years of research.
- For maximal internationalization, Noto.
Rather than need separate fonts for Arabic, Hebrew, Cyrillic, etc Google's Noto has more Unicode language scripts embedded than any other in a single font.
Plus a few others of note:
- For a change of pace, Comic Neue.
Started as a Kickstarter project, this font corrects the typographical shortcomings of Comic Sans while keeping its (IMO underrated) casual character.
- For a distinctly FOSS character, Ubuntu.
While the Liberation font family was funded by Red Hat, the Ubuntu font was supported by -- surprise! -- Canonical and has been a part of the Ubuntu distro since 10.10.
All of the above are available at Google Fonts or the links provided above -- unlike the Liberation family, which ironically is not available that way because of licensing issues(*). (Those wanting freely-available equivalents to Liberation are encouraged to check out the Apache-licensed
Croscore fonts used in ChromeOS.
(*) Liberation fronts are released under the GPL. One interpretation suggests that any document embedding a GPL font is itself subject to the GPL. That posed a possible risk that have inhibited its use, and likely explains why these fonts are not available on Google Fonts. Most open source fonts use either the Apache or the SIL license.