For me it's a toss up between punching and ground fighting. I ultimately picked punching though.
Rationale. I'm not sure it's the right or wrong choice or the better or worse of the choices, but I fear that close range more, and I come from a culture of hands, plus I simply have confidence in what good hands can accomplish.
Best case though... you're well rounded.
Or in other terms... a JKD badass. (I'm convinced Jason Borne is the baddest man on the planet, by the way)