I'm a big believer in making working out something closer to play whenever possible. A recent Men's Health article may have had the ultimate example of that.
Erwan Le Corre is a Frenchman who has set up a camp in Brazil dedicated to workouts that resemble play and emphasize moving as nature intended. In other words, they're fun, but damn hard.
Check out this video to get an idea of what he's preaching. The Men's Health story has some simple ways to incorporate his ideas into your workout.