This question can lead to very opinion-based answers, so it's hard to give a good answer.
However, based on my experience JBoss is one of the most fully-featured, if not the most fully-featured of all Java EE containers. It has excellent integration with Eclipse. There is also an excellent in-container test framework you can use to run your tests in the JBoss container itself called Arquillian which I've found to be excellent (technically though Arquillian can work with several different containers).
I think you need to consider your needs. JBoss is the most complete, but also one of the heaviest containers. If you don't intend on using all Java EE features you may be able to go with something lighter light Tomcat.