Have you ever tried developing an enterprise level Java application with 10,000 lines of code in notepad? Believe me, you need more than notepad in this situation!
From the top down:
- notepad++ for all things general (HTML, CSS, very quick java apps, random code that I haven't got an IDE / IDE plugin for)
- Dreamweaver very occasionally when I need to modify websites and can't be bothered to hack around with the HTML underneath
- Netbeans for all "heavy" development. Enterprise scale projects, any reasonable sized application, that sort of thing. And no - not just Java. It supports many more languages these days - C, C++, Python, PHP, Ruby...
Notepad I tend to use as a last resort these days, especially when notepad++ is available. It's just as quick and easy to use, but its syntax highlighting and better shortcuts make it much more productive and clear to work in.