Sameen Shaw from Person of Interest
With The Machine projecting a roughly 2% chance of survival, Shaw literally took one for the team. She leapt out of an escape elevator to press a manual override button that would send Finch, Reese, Rusco, and Root to safety. By leaving the elevator, she knew she would have to take on Martine and her operatives, facing a near certain death.
Watch Person of Interest on CBS.