Krav Maga is a modern system of Israeli unarmed combat. It emphasizes striking early, hard, and often with immediately crippling results.
I dunno. YMMV as they say. I've heard that civilian training like you might get at a strip mall can be complicated and convoluted. On the other hand, there are plenty of professionals who swear by this stuff.
As I've said before, going unarmed against zombies -- well, any of the bogies and boggarts we discuss, really -- ain't a good idea. But you gotta have something to fall back on, and it does teach you how to move correctly in a fight. The thing about krav is that it isn't some ancient, sacred art that was optimized for fighting armored warriors on horseback. It exists in the here and now and understands mobility -- and also the kind of encumbrance that modern warfighting gear can have on a fighter.