What is the best test of overall fitness?

There have been different types of athletic events to test the various aspects of fitness, few however, truly test overall fitness at an elite level.
There are many endurance events around the world as well as many strength & power events.
What I watched this weekend tested all of those: The Reebok CrossFit Games had 15 tough events over a 4 day period. There was swimming, mountain biking,  running, Marine Corps obstacle course, sledge hammer work, shouldering, yoke walks, and more.
While there are age categories, there are no weight categories.
If you missed it, there will be archives available on the CrossFit Games website.