The best Java IDE today is eclipse.
No need to waist more time  on other IDE's.

Eclipse may be the best "FREE" Java IDE today, but
IntelliJ IDEA is much better than Eclipse.

Although the Eclipse's UI and LnF is more appealing
than IDEA's, but IDEA is much more productive.
Somewhere I read in a weblog that IDEA's refactoring
tools are noticably faster than Eclipse.

I was wondering if Eclipse provide a strong support for Web development in
terms of plugability to Web/Application servers such as Apache Tomcat or
Bea Weblogic.
Also if it comes with a HTML/JSP editor and provides good debugging
environment for, e.g., JSP pages.

I have used JDeveloper which seems to be very friendly in terms of
connectability to application servers developing JSP pages etc.
Can we expect the same functionality in Eclipse?

Existing plugins Set:
1)MyEclipse Workbench.
(Not bad, but comparing JDeveloper it is very
primitive) (29$)

2)IBM Websphere Studio (It is more powerful than
JDeveloper but it is very heavy.(includes 1500
plugins)) (2500$-10000$)

I am using JBuilder for years and I am totally satisfied with it. There is a free persoanl version of JBuilder available for download in http://www.borland.com you can try it. However, the Enterprise version is very costly.

I believe that an IDE is a tool to help the team members to develop your product faster. So it shouldn't be the focus of a developer. Some functionalities are really required. In other hand working with a very huge IDE with hundreds of plugins and functionalities may practically waste your team members' time. This is my experience from several projects.

Don't forget that no professional driver will use an automatic car in racing. A combination of facilities and manual control is always the most efficient way.

We are using: JBuilder + CVS + LDAP Authentication + ANT + WebLogic (and Orion)

I've used Eclipse at work for a while. It's Web Development tools
are nice. Eclipse is plug-in based and u can find many usefull
plugins or write your own. It's editor will work fine with jsp
taglib, Hibernate, ... and any defined xml format code completion. (
You may just need to copy that plug-in to add these
functionalities. )
The only think that made me angry from Eclipse was it's huge memory
usage. after you deploy a big EJB application in it, it will eat all
of your memory. ( here IntelliJ IDEA works  better ) but in average
projects it works fine and is the BEST SOLUTION of IDEs i think.