How can one talk of editors and not talk about the de facto standard in the .NET world—Visual Studio (VS, the paid one) and its free counterpart, the Visual Studio Express. The debugging support of VS is one of the best. Before you think about how VS is useful for web development, let me point you to a few extensions such as:
Web Essentials (available at http://vswebessentials.com/), which has support for HTML, CSS, JS, TypeScript, CoffeeScript, and so on
Node.js tools for Visual Studio (available at http://nodejstools.codeplex.com/), which has editing, IntelliSense, and NPM support
Package IntelliSense (available at https://visualstudiogallery.msdn.microsoft.com/65748cdb-4087-497e-a394-2e3449c8e61e), which has NPM and Bower package IntelliSense
Task Runner Explorer (available at https://visualstudiogallery.msdn.microsoft.com/8e1b4368-4afb-467a-bc13-9650572db708), which provides a task runner for Grunt and Gulp directly within VS
The earlier free versions of VS were called VS Express editions, but now they are called the VS Community (available at https://www.visualstudio.com/en-us/products/visual-studio-community-vs). It supports coding in C++, Python, and HTML5 (along with Microsoft languages) and for Node.js and JavaScript too. So, this IDE is an excellent choice for people who're already used to VS.