Someone once told me to be sure to include a team sport on my resume, so that employers could see that I know how to get along with others on a shared goal. Now that I've been there and also from the other side (as an interviewer/employer), I'd say, screw that - write what you really do, and enjoy talking about it. Assuming the employer can listen worth a damn, it should be apparent enough when you converse whether you can work well with others.
Anyway, I prefer exercise done alone or with a partner - much more efficient, time-wise and results-wise.
This Chinese martial art is like graduate school for fighting. Definitely nonlinear in movement, attack, and defense - power and speed are generated from twisting and efficient body mechanics, not muscle alone. There is Boston chapter of students studying under one of the greatest Ba Gua masters in the world.
Lately, I've gotten interested in Pilates for exercise, since it is based on a deep understanding of the human body, much more so than bodybuilding, aerobics, etc. My favorite free resource on the topic is Think Pilates, which is pilates for smart people; a website recommended by a friend, it provides much more usable information than other sites, which tend to be too spare in details, or too commercially oriented. I combine it with a DVD or group classes, and that works for me as a beginner. As for the particular Pilates method, I recommend Stott - modern science meets J Pilates' original method. How does Stott Pilates ab workouts beat the plain ol' situp, for instance? By focusing on principles - keeping those scapulae engaged while doing the 'hundred makes a huge difference, but a lot of instructors seem to gloss over that detail.
Ballroom dance gives a whole new meaning to teamwork. Come by the UMass Ballroom Dance Team and find out for yourself.