I find the Bitter (download link) font very pleasant to use, it reinforces the “black” side of the text, gives a better contrast impression, and yet, does not take up too much space and can display a lot of characters on a page, in a fairly balanced way…
The Amazon Ember font is also very nice, it can be downloaded here.
How to install a font?
It all depends on your e-reader! On PocketBook e-reader, just unzip the .zip file on your computer, and copy-paste the font files into the folder system > fonts.
On a Kobo e-reader, you need to create a “fonts” folder at the root of your e-reader (once the e-reader is connected to your computer in USB mass storage mode) and paste your font files into it. Simple, isn’t it?
Any question, any doubt, any font to recommend? Feel free to write a comment below!