Top-Notch! We use this plugin all the time

Custom CSS and JS is easy, customizable, simple to use and modify. It makes CSS custom code input a breeze, and even some of my clients found it comfortable enough to modify themselves!

I cannot recommend this plug enough – it also has robust controls and the ability to add CSS to the admin interface (invaluable!) and control where and how the CSS is added.

This plugin is the #1 for Custom CSS and JS. This is a plugin we install in every new website.

I’ve tried them all, and this one is the best hands down.