5. Chases Hand
We all know Jack makes the tough decisions when the chips are down. In series three when his partner, Chase, finds himself attached to a ticking chemical bomb there is only one thing to do. His hand has to go...with an axe...wielded by the father of his girlfriend. It is horrific for the characters to think about but with no other option Jack does not shy away from what needs to be done. As a viewer I remember watching as the tension grew expecting the device to malfunction or something dramatic to spare Chase's hand, but it never came. It is yet another unforgiving scene that showed how nobody was safe in the world of 24.