Andy using his powers, which he's just starting to learn how to use, to destroy several of the Sentinel drones chasing the family and the mutant underground. Note, these are the same drones that Marcos's powers barely scratched.
Lauren using her powers to close Blink's portals.
Reed using his knowledge of the law and calling Turner's bluff.
Lorna uses her powers to throw a metal table during a prison fight while wearing an inhibitor collar.
Reed jumping out of a van to let an innocent mutant mother and daughter get to the Underground and lose Turner's Sentinel Services team. Also counts as a Heartwarming Moment. What makes it better is Reed's retort to Turner about botching their deal.
Jace Turner: We had a deal, Mr. Strucker. Reed: And you can shove that deal up your ass.
John taking out his old friend Pulse so the others can use their abilities— especially considering that apparently the closer a mutant is, the more painful the effect is, only for John to power through and knock him out with one punch.
Trapped in a truck specifically designed to contain Lorna - zero metal to manipulate - Reed tells her to use the surgical screws in his leg, potentially doing permanent damage to his leg to get them free.
After Lorna and Reed have been rescued, Caitlin pulls up in a getaway vehicle big enough to evacuate everyone. Considering they were separated from Clarice at the time, surrounded by Sentinel Services, Pulse could have regained consciousness at any moment, and Caitlin has up to this point mostly acted as The Medic, her courage in this situation is incredible, and the look of utter relief on everyone's' faces when they see her says it all.
Caitlin and Lauren working together to save Harry who was shot while rescuing Reed, combining Lauren's mutant power with Caitlin's good old medical knowledge to get the bullet out and seal the artery it hit.
Otto Strucker showing exactly why the mutants from the Strucker line are so dangerous, when he overcomes Pulse's Power Nullifier abilities by brute force alone even after being shot twice in the chest.
When Lauren and Andy join hands, their joint power exceeds their interrogators' ability to measure it, and does significant damage to a room made of adamantium, the hardest known substance in any Marvel universe.
In a frightening way, the ability of Esme and her sisters to deal with Sentinel Services.
The Season 1 finale gives us two frightening, yet awesome moments:
Andy and Lauren using their combined Fenris power to destroy Mutant Underground HQ in order to cover everyone's escape, in the process wiping out all the Hounds.
Also from the finale, there's Reed's Rousing Speech to the defenders of the headquarters when Sentinel Services shows up to attack.
Marcos's Shut Up, Hannibal! and threat to one of the Frost sisters when he, John, and Clarice find out they have convinced Lorna to assassinate Campbell and Senator Mondez before they make it to DC - his rage actually seems to frighten her.
Season 2
Caitlin Took a Level in Badass over the 6 month Time Skip when she disarms someone who might know where Andy is located at gunpoint and walks away with only a bullet graze (she even stitches the wound herself, apparently without using any anesthetic).
Lorna giving birth to her daughter. At first Lorna doesn’t think she can survive the birth but then Frost sisters show her a future where Mutants are free and safe and her child living in that utopia. It gives Lorna all the strength she needs to pull through.
Marcos resisting the combined strength of the Frost sisters' telepathy.
Andy and Polaris combining their powers to destroy the power generators for the mutant inhibitor collars. Not for one site but all of them. Cut to various prisons and camps across the country where the mutants realize their powers are back and are soon staging mass riots and escapes.
Andy and Lorna teaming up with the rest of the Mutant Underground to save John from Purifiers. The rescue goes as smooth as possible as the Mutants outright decimate the hate group.
A minor one-episode Mutant finally does what we've all been hoping for and completely tears down the veneer of allegory regarding the persecution of Mutants, as when Turner asks why he ran if he's innocent, he simply replies "My granddaddy didn't need a reason to run from the Klan, and neither did yours."
Lauren has a rematch with Andy during their mental mind share and almost effortlessly beats him. Andy ends up waking up with a bloody nose as a result.
As Caitlin and Lauren are helping a group of Morlocks escape the Purifiers' attack on the tunnels, they're cornered by the police. In response, Caitlin whips out a gun and fires a few shots through the windshield to distract the cops. As soon as they're ducking for cover, she then puts the car in gear and rams through their barricade, making a break for it.
Also, while it's a tearjerker, there's the Morlocks' Last Stand against the Purifiers as they try to buy time so that the noncombatants can escape to safety.
John goes One-Man Army on Jace and the Purifiers to allow Marcos, Lorna, Reed, and Caitlin a chance to escape and save Andy and Lauren from the Frost sisters.
With help from Erg, John manages to defeat Jace and give the guy a well deserved beat down before stopping himself from killing him.
Lorna using her friendship with Esme to get her to turn on her sisters, freeing Andy and Lauren from their control and giving Marcos an opportunity to knock them out.
One particular moment from the resulting face off with the strike team: when an invisible Fade starts choking Reed, Caitlin quickly determines where he is and empties a clip into him.
Reed's Heroic Sacrifice in order to kill Reeva. Taking advantage of his unstable powers and turning himself into a human bomb taking out not only Reeva but her Mooks in the building as well.
What makes this scene even more epic is the fact that Reed already won. From the moment Reeva used her debilitating scream, it already began to destabilize Reed's disintegrating abilities, sending him to the ground. Since she walked closer to him during this, he could have just crouched there and waited for his powers to fully activate. But instead, he found every last bit of strength to stand up and look her in the eye to deliver his Pre-Mortem One-Liner, leaving Reeva in shock.
