Netbeans by far, however notepad++ is indeed a very good app. but i think Netbeans has a lot more " support " inbehind it when it comes to error correction and control.
Hi i think it's better to focus on programming, choice of ide is wasting time. to make some good code notepad ++ or gedit are fine, 'cause a text editor it's all you need.
When I'm on linux, which is most of the time, I like to use Bluefish. When I'm on Windows I use notepad ++
I wonder what kind of web application you guys develop using notepad++. Are you talking about the class projects such as generating the fibonaci series? Even netbeans is not a PHP IDE. It is an IDE basically for Java. It does has integrated tool for PHP but still it is not a complete PHP IDE. Most of the IDE mentioned are not for PHP. They are for other languages like Java. Web development is not just coding. Design is an integral part of any web application. Any IDE without design interface is useless for Web development. Dreamweaver and PhpDesigner are real PHP IDE. PhpDesigner lacks the designing interface (though it is called phpDESIGNER). But it does have some very unique and useful tools. (I have used phpdesigner 7 but new versions are available. don't know about that) Dreamweaver is the best Web development tool that i know. I do not know of any other that even come close to it. It has lots of features for both designer and well as a programmer. A programmer seldom uses the design view but a web development consists of both programming and designing task and ask a web designer what dreamweaver means to him.
For PHP I would recommend PhpStorm. It supports FTP/SFTP synchronization, integrates well with Subversion, CVS, Mercurial and even with Git. Also, it supports HTML, CSS, JavaScript and handles language-mixing well like SQL or HTML blocks inside PHP code, JSON, etc. But if you need Ruby you can try another IDE - RubyMine with same capabilities but for Ruby.
I use NuSphere PhpED ... notepad++, for me at least, is an advanced text editor, not an IDE, can't comment on the others as I don't know them.