When managing custom Java applications hosted inside WebSphere Application Server, what JMX metrics do you find most useful for monitoring performance, monitoring availability, and troubleshooting problems? And how do you prefer to slice and visualize those metrics (e.g. chart by top 10 hosts, graph by app, etc.).

The more details I can get, the better, as I need to specify a standard set of reports which IT can offer to owners of applications hosted by IT, which those owners can customize but many won't bother. So I'll need to come up with a bunch of generally-applicable reports which most groups can use out-of-the-box.

Obviously there's no one perfect answer to this question, so I'll accept the answer with the most comprehensive details and I'll be generous about upvoting any other useful answer.

My question is WebSphere-specific, but I realize that most JMX metrics are equally applicable across any container, so feel free to give an answer for JBoss, Tomcat, WebLogic, etc.