From DS9 'A Call to Arms'
That is a great pic of Kira, one of my favorite SciFi women. That' would be a vote even without the animated gif!
I decided to upgrade to the gif, though, 'cause lots of entries are just head shots. And Kira givin' the order to wipe out the station's computer core was one of the bravest things she had to do, 'cause she was still there after it was done & had to face the enemy.