I would babble excitedly about it (it is my favorite show: yes, more than Firefly), but I’m strapped for time and no words of mine can do it justice. It’s machines from the future, it’s time travel and causality, it’s Lena Headey as Sarah Connor and Summer Glau as one of the aforementioned machines, it’s intrigue and mystery and philosophy, plus robots punching each other and shooting things with guns. Just go watch it; it’s awesome.
ETA: Evidently it is USA only, guys. Sorry about that; the rest of the world deserves robot awesomeness too.