The Pentaho BI suite has an extensive set of GUI apps. They used the SWT toolkit from the Eclipse project. SWT has a fairly broad fan base, although personally, I have no problems with Swing.
After the demise of Visual Caf�, there weren't any decent
IDE GUI app designers to speak of for a long dry spell. Fortunately, this ended with the introduction of IntelliJ version 6. One thing that I liked particularly about it was that - unlike earlier tools, it didn't require that the finished product include proprietary code - the created output was 100% pure generic Java. Which is important when you're creating an open-source project.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.