The answer to this question depends on the functionality that you might need, as well as on what you work with. Most likely, most of the functions that you need you can find in any popular PHP editor. The rest is a matter of taste.
There are many good editors that you can try. I would single out the following:
- PHP Storm (according to some – it’s the best, but it’s paid)
- VS Code (free, I chose for myself, I just liked it)
- Atom https://atom.io/ (free, also very interesting, github development)
- Sublime Text (there is a paid and free version)
- Netbeans (free)
- Codelobster (free)
Go through this list and try several editors, this will take time, but you can arrange for yourself a comfortable working environment.