Java developers frequently discuss about what IDE is BoB (best-of-breed). Well, I don't think it's possible to choose one, to be honest.
Eclipse is feature-rich but the GUI in som areas is horrible and it tends to brake up with updates, also support for amd64 linux was missing for some time. It has support for Android, it has Wolips and much more. There are also project for non-Java developers like PyDev, although this one lacks the comfort and power of Java toolset.
Intellij Idea has best productivity for the things it supports. The set of supported refactorings and some other tools make development a joy. Some plugins tend to throw exceptions but IDE is usually not affected. Great GUI. Does not support so wide scale of technologies as Eclipse but it's worth the money. JetBrains has to be customer oriented to stay in business ans they do they job well.
Netbeans I know not so much. I like its support for JSF. I think in version 6.5 it really started to be usefull. I hope Orcale won't toss it up trying to force people to JDeveloper.
Conclusion - I use the IDE on wihich I can do the job best. Sometimes its Eclipse with Idea for refacoring, sometimes it's only Eclipse or only Idea - if both support the desired technology well, I use Idea.
