What's cool about netbeans
There are quite a few things about netbeans that makes it really attractive. Let's forget the big things like the fact that netbeans is open source etc and look at some of the small things that makes it fun to use.
One of the features that I really like is that way it opens up resource bundles. When you are trying to internationalize an application having to open and switch truth several different property files is such a pain. Netbeans eliminates that pain. When you open the main resource bundle, netbeans will open the other localized versions as well and display them all as a table. What a cool and convinient way to edit the files.
What else is really cool? the profiler. Once you get the hang of it, using it becomes fun.
Another feature I like is the ability to load modified classes during debugging sessions.