Magic5 Clean easy-to-read 5-pixel wide sans.
This font was designed using FontStruct in 2008 as an attempt to create a very clean and easy-to-read system font that was 5 pixels wide. It is very generic looking with just one extra feature being the strong inner curves on "bdpqgyhn". This helped with ZX Spectrum conversion where vertical height was limited to 8 pixels and the descenders were shaved down 1 pixel.
This font is super easy to read and with a simple 6-pixel-wide custom renderer you can get 42 characters per line instead of the usual 32 on a Spectrum screen.