top 5 Java IDE

Java applications have earned their reputation for being highly scalable and platform-independent .Since java(i.e. the java_development_kit or JDK) comes under the category of freewares and distributed widely as an open-source product hence the support available to it is also greater as compared to other programming languages.As such there are numerous IDEs (Integrated Development Enviornment) available using which u can develop your application.
I have been developing java applications for quite sometime and have used a number of IDEs over time. Here's how I rate them:

1.MyEclipse
advantages: 1.lots of plugins for enterprise application development(JSF,JMS,EJB,Struts) 2.very little configuration required 3.almost everything is included within this one installer. all round solution 4.very well documented.lots of help available within it 5.a real smart intellisence. 6.design modes available for configuration files
disadvantages: 1.its not a freeware.one needs to buy n its expensive 2.system requirement is comparatively higher than other IDEs (min 1gb RAM required)

2. NetBeans
advantages:1.freeware. 2.very well documented and lots of support(both within itself & in the internet) 3.good number of plugins
disadvantages:1.UI looks crappy (metal), icons suck. 2.no refactoring or refactoring templates (try/catch, rename field, etc...). 3.no JSTL-EL support in syntax highlighting/code completion. 4.cannot wrap arbitrary text in editor.

3. Eclipse
advantages:1.its a freeware 2.lots of plugins available 3.highly scalable
disadvantages:1.very little inbuilt support 2.though its highly scalable.yet configuring them into projects can be a problem

4. IBM RAD [Rational Application Developer] & JDeveloper[ by Oracle] :i rate them equal because both has got their own pros n cons. i have used both of them. they are highly used by various corporate group because they come with real powerful websevers which gives a number of customization and services.They are packed with features.

6. BlueJ
advantages:1.its a freeware. 2.very small in size as such easy to transfer the software(one can even mail) 3. the UI is very simple [probably the best IDE for school kids] 4.good for core java applications (like applets)
disadvantages: 1.has got very little functionality 2.only core java aplications can be developed 3.plugin support is very low. 4.the typing intellisence is not very smart