Gentium is an open and free font with amazing quality and character coverage: https://software.sil.org/gentium/ https://software.sil.org/gentium/ Deja Vu is al

Gentium is an open and free font with amazing quality and character coverage: https://software.sil.org/gentium/ https://software.sil.org/gentium/ Deja Vu is also open, and pretty nice for screen usage. As for non-free fonts, I love Gill Sans.