Recently I've been doing some work on a desktop Java application and I decided to use Eclipse and my IDE. I hadn't used it for a while (since I did my 4th year engineering project – almost 3 years ago now) and I'm loving all the features and how easy it makes some things.
The stuff in the "Source" and "Refactoring" menus especially are a real time saver: being able to automatically create getters and setters, constructors, extract methods, rename methods and variables and a bunch of similar operations are made trivial rather than tedious. The ease with which you can create and run unit tests has also meant that I'm actually keen to create unit tests for all my code – Eclipse will create all the relevant classes and test methods for a given class for you.
Some of the available plugins are really good too. I'm using EclEmma to perform code coverage analysis and direct my test writing. I haven't set up any source control for my project yet but I hope to use [Subclipse] to connect to a local Subversion repository automatically. I also installed the C/C++ Development Tools (CDT) package but haven't attempted any C++ development.
While in the past I thought the layout of the IDE "workbench" was far too cluttered, I have since changed my mind. On a 22″ monitor there's plenty of room for everything and being able to access everything easily saves quite a bit of time. At the same time I can have information views for the package explorer (displaying all the classes in the project), coverage reports, an outline of the current class and a test report. I'm also amazed at how customisable the whole thing is: views can be moved around basically at will.
I've only been using the IDE for a week or so but I find it really helpful for Java development. I would also like to try out NetBeans to see how good it is – version 6.0 was just released.