In my opinion, most of the people who brag about using Notepad like editors with very simple functions probably just don't do this stuff professionally.

When you need to get things done, a proper IDE with syntax coloring and code completion, and most of all - error highlighting is the best choice.

If you want a good HTML editor - Dreamweaver's the best I know of.
The best CSS editor I know of though is Microsoft Expression Web.

But I personally use NuSphere's PhpEd for PHP, HTML and CSS. Hell, it even supports Smarty templates in HTML.