I use editplus (http://editplus.com/) and dreamweaver 2004 mx. This is after trying many others including PHP Edit, eclipse, PHP Designer, etc.
I like editplus because its simple but feature full. Good spell checker, supports multi programing languages, works well under wine in linux, and is customizable. Cost $30
I love dreamweaver because you can do just about anything with it, But it cost $300+. There are many extensions available for it and it is very easy to use. It also use PCRE regular expressions in its search/search and replace (same regex engine as one of php's), which can make script hacking allot easier, plus it helps when your trying to create complex regular expressions for scripts.