WeBuilder is my primary HTML, CSS and PHP editor; it's as rich in features as Adobe Dreamweaver, but its interface is as far as can be from Adobe's bloated mess and so easy to navigate and use that the program has basically zero learning curve. It has advanced syntax highlighting and code completion -- which makes even php coding super-easy -- for HTML5 and CSS3 too, and the preview tool is great. The price is not super-cheap (about $60) but, considering what you get, the program is worth every single penny.
EditPlus is an advanced text editor - with syntax highlighting and code completion - that can also be used for html and css editing as well as a source code editor; the interface looks quite basic, but it has all the features you need to fully code a css stylesheet and a html page. I recommend the program also because it allows to view a real-time offline preview of some php files; the price is quite cheap too, which makes it a must-have for every designer.
Just Color Picker and Colorpicker are two very tiny, very easy to use color pickerd; they have very precise magnifiers to help you select colors from an image, the color editing tools are the easiest I've ever worked with; Just Color Picker also comes in a portable version, so you can use it without needing to install it. I've tried several color pickers for Windows through the years, but these are definitely the best and the only ones I can whole-heartedly recommend.
WinRar is the absolute top program to deal with compressed archives on Windows; it's easy to use, quite customizable, and completely compatible with all compressed files formats. It's actually a pad program, but if you don't mind the "purchase" pop-up at opening you can use it forever as the trial never expires -- and if you want to buy it, it's quite reasonably priced.
Paint.NET is an easy to use and light-weight photo editor; it's a fairly basic program, but it has all the features you need -- including layers, magic wand tool, text tool, etc. -- to make quick edits to your images. The program is 100% free, and comes in handy when you need to make a quick change to an image and don't feel up to use Photoshop....all in all, quite a useful tool to have on your pc.