In the episode "Deep Trouble", Dizzy Flores single-handedly takes down multiple Arachnid warriors in a display of combat acrobatics and marksmanship to save one of her downed teammates. When it's over she hears clapping and looks up to see the rest of the squad, including their hard-nosed veteran commander, acknowledging the show.
Five Words: Higgins with a Missile Launcher. The timid reporter even manages to nail a Hopper threatening Lieutenant Razak. Doubles as a Crowning Moment of Funny.
The episode "D-Day" gives pretty much everyone a CMoA, but special mention goes to T'Phai, for killing three Warrior Bugs...with three bullets. Bear in mind that you normally need to put half a magazine into one of those things to take it down.
More proof of T'Phai's badassery. In "The Face of Truth", after he's freed from his Control Bug and the Roughnecks are storming the Xylon mine, they tell him to sit tight while they handle things. During battle, Lieutenant Razak is hit by constrictor spray. Higgins goes to help him, but a skinny is sneaking up on them from behind. Abruptly, the enemy is zapped with an X-ray blast. The Roughnecks look up to see T'Phai sitting on a ledge above them, holding a gun nonchalantly.
T'Phai: I was bored.
Carmen versus a Kamikaze Rippler in "Swarm". Her retrieval ship has machine guns mounted on the front, but nothing to shoot down the bug that's currently behind her...so she Wronski Feints it into a cliff.
Carmen: *to her copilot, just before diving* Hope you didn't have a big lunch!
Said CMoA by Carmen is prompted by a Bug CMoA. Four Ripplers close in on two retrieval ships. One bug lands on a retrieval ship's right wing, and casually tears the engine off.
In the Klendathu episode "The Mission," Lt. Razak is weakened by the atmosphere of the planet and the team is forced to leave him behind while hoping a hastily thrown-together antidote will cure him. Later, the team is pinned down by Zander and his swarm of Imposter Bugs. Just as Zander is lecturing Rico on how surprise is the greatest weapon, who else comes swinging in (literally!) but Razak himself, catching everyone off guard.
The Bugs get a massive awesome moment when in "Trackers," the conclusion of the Klendathu campaign, they launch nearly a hundred Transport Bugs all in a massive Batman Gambit to provide decoys for their Queen to escape. SICON is completely fooled.
Brutto's crowning moment comes during "Funeral for a Friend", when he kills a Warrior Bug with his wheelchair.
An earlier one comes in "Captured". The Squad has been taken prisoner by Skinnies, and six or seven of them enter the room to take Brutto and Jenkins for interrogation. Brutto snatches one of their shock sticks and beats down three or four of them before he's subdued. Made even better by his line as the Skinnies close in on him.