The possibility to override any font, justification, indentation and other things with my choice is one of the most important features of my reader.
Serif fonts are great for *printed* books. For a low resolution medium, such as e-ink readers, I prefer sans-serif fonts.
At the moment I use Ubuntu Font. Before it was Gentium.
See some of my older posts
https://www.mobileread.com/forums/sho...4&postcount=10
Search for posts with Gentium, droid, ubuntu, caecilia posted by Kacir for more discussions.