If you like working with WYSIWYG, I found Amaya quite good for the purpose.
I personally use Eclipse with PDT plugin for php/html and a plugin for javascript (I don't remember the name). That makes editing js, css, php and html (if any) a lot easier (all in one place) - I love the ability of Eclipse to auto-complete variable names, function names, html tags, css styles and so on. I tried Maguma Open Studio but it was less elastic (and didn't have parse-error checking afair).
