Atom is a code editor completely free and that can easily be integrated into Git or Github.
Visual Studio Code
Developed by Microsoft, Visual Studio Code has a built-in terminal as well as easy integration with Git. It is however very robust and free.
Notepad ++ will allow you to create your lines of code on a clean and customizable interface. Completely free, however, it can only be used on Windows.
Sublimetext is one of the best known tools. SublimeText helps highlight desired elements in your code to make your job easier. There is a free and paid version ($ 80).
Brackets is very interesting for editing CSS and has many features (such as its ease of highlighting the CSS definitions of the selected <div>), its interface is pleasant and fast, although it knows a lot of bugs.