I like FiraCode font the most, it is just beautiful and supports ligatures. Alternatively, you can browse Programming Fonts or other ligature fonts like Hasklig to see which font suits you.
Theme and font are completely personal taste, but if you like me, please give One Dark and Fira a try, here is how to do that in Xcode, Android Studio and Visual Studio Code, which are editors that I use daily.
This font is free for PERSONAL AND COMMERCIAL USE.
Fira Code Font
License: Free for Commercial Use!
Font Type: OTF
Total Files: 1