One thing to consider is practical strength and fitness. The best work out I've ever gotten has been when carrying lumber, cutting down trees, pulling snowmobiles out of ditches and shit. Not saying you should escape your current life to go live in the forest, but the more you can emulate practical strain, the better. Obvious stuff, but in this day and age of all-in-wonder machines designed for maximum comfort, it's not nearly as obvious as it should be.
And speaking of which, I went down to the damned gym again, and sure enough, there was one car parked outside for every one person on the cardio machines. It's a clubhouse gym, so none of these people would have far to walk to get there.