"I might not be able to stop this, but I won't be a part of it!"
Pope figured out how to kill the Mechs, with the help of Matt, and demonstrated it to the 2nd Mass.
Even after the attack on the alien structure fails, Tom still manages to strike a blow against the invaders by hitting one of the alien fighter craft with a Mech metal-enhanced RPG (basically a one-in-a-million shot), which then crashes into the structure and causes extensive damage to one wing of the structure.
Weaver: "Good shot."
In second season premiere, Mason is confronted by one of the Overlords and its Breaking Speech cherry picking of human history to claim that mankind is despicable. His answer? Punch the guard, take its stun rod, and use it on the Overlord.
In the beginning of the episode we see how much better the group has gotten at fighting the aliens. They kill one mech with a hidden bomb, and then Maggie wastes another one with a rocket launcher.
In "Shall We Gather At The River" Dai uses a (presumably) modified .50 caliber to casually shoot down another alien fighter. This is the second known fighter to be shown down by humans.
Tom handing Pope a thorough ass kicking, for taking a compass from a dead member of the Mass (Jimmy). Multiple people note he nearly killed Pope, with his bare hands.
The long awaited Espheni assault finally comes in "At All Costs". They totally kick the aliens' asses.
Pope and his friends are partying and placing bets on the who will live or die in when Hal takes his father hostage, as they are partying, Weaver walks in. His mere presence quiets the entire room (including The Berserkers), he calmly walks as everyone looks like they're just about pissing themselves with fear, including Pope. Weavers sits down, orders a drink and when Pope tries to approach him cautiously, Weaver grabs him and says , in the most serene tone possible:
Weaver: If anybody tries to affect the odds on that board one way or another, I will personally mount your head on the wall of this establishment.
He then leaves, the room still in terrified silence.
Cochise not only survived a plane crash, he also protected the president with his body, then cross mileson foot until he reached Charleston. While still carrying the President. Cochise definitely earned his "rebel fighter" wings after that moment.
Tom beating the Lotus-Eater Machine not once, but twice. And making a wicked escape from Karen's captivity.
Our Big Bad Karen decides to have a little chat with the 2nd Mass about alliances, and this culminates on:
Karen: And to prove my good faith, I brought you a gift. One that I think you'll like, Tom.
Tom Mason and Lexi's mission to the moon is chock-full of them:
A Villainous Valor one for Scorch, who throws a monkey wrench in Mason's plans by tracking down his ship, bitch-slapping Mason across the room and nearly killing Lexi. Even as he dies, he manages to rip out the ship's pilot mode with his last breath, ensuring Lexi would die with him.
Subsequently, Mason gets to kill Scorch. This is the third Overlord Mason confronts headfront and then kills in battle. He's starting to get good at it.
Lexi choosing to guide the ship to the moon by herself. Which costs her life.