I do not think you can talk about typefaces separately from talking about color themes. Different typefaces will have completely different legibility depending on the background and foreground color. Low-contrast themes are terrible for legibility, and necessitate poor choice of font and font size to compensate.
In 2017, I decided to invest some time in font-shopping; so many good alternatives had appeared since I last looked in 2009. The unexpected result was that I stopped using vector fonts and switched almost everything I do to the X Window System bitmap misc-fixed font.¹ After looking at the alternatives, misc-fixed is still the best typeface for text density and extended computing sessions. It was a typeface designed for black-on-white CRT displays in the 1980s, but works just as well white-on-black on LCD displays today.
¹ Unfortunately Firefox font picker only lists vector fonts, I did not bother to try fixing that.
> Unfortunately Firefox font picker only lists vector fonts, I did not bother to try fixing that.
Fontconfig on most distros is configured to reject bitmap fonts by default. On Debian, it's /etc/fonts/conf.d/70-no-bitmaps.conf. One way to fix that is enabling all bitmap fonts "dpkg-reconfigure fontconfig-config", which might be too much. Another is to explicitly enable Fixed in /etc/fonts/local.conf: https://github.com/stevenrobertson/rc-files/blob/master/.con...
In 2017, I decided to invest some time in font-shopping; so many good alternatives had appeared since I last looked in 2009. The unexpected result was that I stopped using vector fonts and switched almost everything I do to the X Window System bitmap misc-fixed font.¹ After looking at the alternatives, misc-fixed is still the best typeface for text density and extended computing sessions. It was a typeface designed for black-on-white CRT displays in the 1980s, but works just as well white-on-black on LCD displays today.
¹ Unfortunately Firefox font picker only lists vector fonts, I did not bother to try fixing that.