Dica testada no Fedora 26. Apenas quem acha que as fontes do Fedora estão um poucos feias e serrilhadas.

Primeiro, instale o RPM Fusion:

sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

Depois:

sudo dnf install freetype-freeworld gnome-tweak-tool
sudo gedit /etc/fonts/local.conf

Cole o conteúdo:

<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
<match target="font">
    <edit name="antialias" mode="assign">
        <bool>true</bool>
    </edit>
    <edit name="autohint" mode="assign">
        <bool>false</bool>
    </edit>
    <edit name="hinting" mode="assign">
        <bool>true</bool>
    </edit>
    <edit name="hintstyle" mode="assign">
        <const>hintslight</const>
    </edit>
    <edit name="lcdfilter" mode="assign">
        <const>lcddefault</const>
    </edit>
    <edit name="rgba" mode="assign">
        <const>rgb</const>
    </edit>
    <edit name="embeddedbitmap" mode="assign">
        <bool>false</bool>
    </edit>
</match>
</fontconfig>

Salve e feche.

Abra o Gnome Tweak Tool:

gnome-tweal-tool

Deixe as fontes assim: Com Slight, Greyscale e Fator de escala 0,90.

Faça logout e login novamente.

Fonte: Font rendering in Fedora 25 : Fedora