Hockey, obviously, BECAUSE ITS THE GREATEST SPORT ON THE PLANET (both our real one, and the alternate universe that is FFVIII).

Sports go hand-in-hand with military as pass-times. For example, my cousin is in the navy, a ships diver in fact, and has played hockey for years, competitively with the Navy Team in senior leagues. He's over 40, and still playing, often with and against 20 something year olds just out of junior who joined the military.

On keeping up with younger, faster opponents he once said to me "it don't matter how young (or old) you are when you're tearing someone's jugular out".

Of course, he was kidding, but nonetheless he is an enforcer, and is notorious for fights. But it just goes to show that an intense, fast, rough game like hockey in which fighting and rough-housing is allowed (but slapped on the wrist with a 2 or 5 min penalty) would be perfect for military personnel as a past-time. Same would go for football (gridiron, american style) and rugby.

So yeah, I vote hockey.

And wow, did I ever ramble in this post .