I've found that classes are best for me. A few years ago I started going to an aerobics class that emphasized strength. Then I did a boot camp. In 2010 I started doing Crossfit and hope to do it the rest of my life. They push me well out of my comfort zone, and the group aspect makes it both competitive and collegial.
Last year I decided two times a week was good enough for me and it's worked. I'm in fantastic shape.
I started doing crossfit about 3 months ago and absolutely love it.
Being a global and pretty standardised thing there are gyms all around the world you can attend. Despite the language barrier you still know what to do. For instance I am in Tokyo currently and about to go here: http://chikaracrossfit.com/ If I were in Denmark then I’d love to drop in here: http://butcherslab.dk/
Just as being a developer allows you to network globally, crossfit does too.
Last year I decided two times a week was good enough for me and it's worked. I'm in fantastic shape.