Season 2 Episode 10 (Second Wave): Julian averting his destiny by explicitly renouncing a violent end to Kiera while proving to his group why he's their leader.
Theseus demonstrating what he thinks of the slave labor camps of the future, rescuing someone along the way.
Emily fights Travis hand to hand, and actually manages to mildly annoy him. That might not sound like much, but it's more than the cops, a prison riot, and every single gang in the city ever managed. She would have done better if she had known he was a super-soldier, since she would have skipped the warning shot and gone straight for the kill.
Season 2 Episode 12 (Second Time): Kiera getting the best of Travis on the elevator.
Season 3, Episode 1 (Minute to Minute): Kiera and Garza teaming up against the Freelancers in the stairwell in a marvelously choreographed fight scene.
Again in "Minute to Minute" when Emily eliminates Escher via Boom, Headshot in Alec's new timeline.
In "A Minute Changes Everything", a Past!Alec Sadler wowing the board of directors with his on-point talk after he'd earlier flubbed it reading off index cards.
For a few moments in "3 Minutes to Midnight", Liber8 realizes they actually pulled off changing the timeline to get rid of the Corporate Congress. That bit of awesome immediately gets sunk like a lead brick when they find out it led to an even worse timeline than the one they had inhabited.
The fact that Kellog, the least physical yet most weaselly member of Liber8, is the one who ultimately survives all that horror. Not only that, he then steps up and puts a plan in motion to fix it.
Alec stabbing a Freelancer with a pen. He didn't manage to kill the guy, and in fact the guy just pulled it out like he was removing a splinter, but it was still pretty badass.
Sonya concealing explosives within her skin to take out Dillon without him in the least suspecting it.
Practically the entire Season 3 finale. Kiera's speech, in particular, saying she doesn't have to agree with Liber8 but she will work to make a better timeline than she herself knew. The only thing Travis needs to say in response is: "Let's get to work."