I do a huge variety - usually something different everyday. it all depends on my motivation and my strengths that week. My job takes a lot out of me emotionally and physically.
Some weeks I feel strong and can do more - so I run more. Some weeks I am spent and can barely drag myself out of bed - so I spend more time taking it easier on the elliptical or stationary bike. Some weeks I need the motivation of a group class, so I take more classes.
Most weeks I do some combination combination of: running, StepMill, kickboxing, and elliptical.
Hiking. ...here in the Phoenix area, we've got a ton of steep mountains scattered throughout the city. Powering up Squaw Peak or Camelback Mountain will get your heart going in a way that no exercise machine can touch.