Chase saving Leo from Donald's super strong malfunctioning battle suit, all without revealing his bionics to Leo's Grandmother in "Exoskeleton vs Grandma"
Leo's takedown of a berserk Eddy in Night of the Living Virus with a laser reflector. Note that he has no bionics and is a scrawny kid, against an A.I. that has helped to train the young bionic heroes.
Adam punching an asteroid that's about the size of a mini van into rubble with a single swipe in Mission:Space
Adam gets another one for completely fooling Principal Perry and getting him, Bree and Chase out of detention. in Missin' The Mission.
Donald, Chase and Adam each get one, for beating a whole group of thugs together in "Quarantined"
Perry vs Spike: Round 2.
Leo vs. Marcus in "Leo vs Evil", topped off with Leo outsmarting Marcus with the same trick Chase used to beat Adam at arm wrestling enough to take Marcus' robot control and use it against him. And when that failed, he managed to escape while Marcus was distracted. Leo's badassery increased more and more in season 2.
Adam gets special mention in the fight with Marcus by unlocking his hidden power, which is a major Kamehame Hadouken. Doubles as a heartwarming moment because it was in response to Marcus trying to hurt Leo.
Bree likewise gets a mention, for being the only one of them to actually successfully stall Marcus, thus distracting him long enough for Adam to save Chase.