I have to put my vote in for Crossfit, as the progression has been undenyable for myself and the people I train with. The results speak for themselves - check out the scores from the 2008 Crossfit games. They are some of the fittest people on Earth. If you have your doubts, try one of the workouts used in the Games and see how your time stacks up against these guys. You will be humbled.
Although I find Crossfit to be applicable to all of the domains of fitness (after all that's the purpose), it is not for everyone.... at least not the mainsite page. Just like any program, you can tailor it to your specific goals.