I like having a custom font, usually cursive but this font has been easy to read and fits my current zombie theme.
First find a font file that you like in .TTF format, download es file explore or use one you are familiarwith. Go to system/font and paste your new .TTF file. Set permissions to writeable and swap names of HYSerif_Regular and your new font. Move HYSerif_Bold to a folder on sd card for a back up. Then turn permissions back to where you found them.
Now go to settings>display>font and select HYSerif which is now your font because you chanted your "xy.TTF" to HYSerif_Regular.TTF in the previous paragraph.
Have fun. Doing this is at your risk but I have do so with no issues.