I like Dreamweaver, simply because it gives you the layout you need when you open a new document, has code intelligence for every lang, and has buttons that type the most-typed things in a specific language. Aside from that it carries the best JavaScript support, and the best CSS support. It even helps me out when I am trying to position something perfectly--if it works in Dreamweavers browser, it works in every browser. It does lag sometimes, so it isn't for small projects, or PHP projects. Its PHP support is very minimal, and I don't think it supports content highlighting for OOP.

Notepad++
I can't live without it. The thing is extremely useful for learning a language. My favorite part about it is that there is no lag whatsoever. It seems as lightweight as notepad, but supports multiple documents (tabs) and can be configured to highlight syntax.

Zend Studio
Laggy like Dreamweaver, and kind of overwhelming if you don't spend hours in the help and documentation screens. All in all, I don't code much in PHP, so I can't really say much about it.