The entire climax of episode 5. Haruka riding her guitar like a flying surfboard, wearing a bunny girl outfit for no reason whatsoever, fighting a skyscraper-sized robot with five guns that fire shells the size of cars.
Another moment during ep 5's climax, Mamimi keeps calling for Tasuku's help, Naota becomes a Big Damn Hero while striking a Captain Morgan Pose on Canti's alligator-like jaw, confidently and intimidatingly demanding she stop calling him by his brother's name. This, coupled with the amazing lighting and all around wonderfully animated scene, make for quite the CMoA.
Naota does it again in episode 6, where he becomes Atomsk, Dual Wielding two guitars (until he combines them into a double-necked one), flies towards Haruko at breakneck speed... to kiss her and say that he loves her.
Haruko's introduction. Issuing a Crash into Hello with a (seemingly) random boy, administering a Kiss of Life, then smashing him in the face with a guitar. Tells you everything you'll ever need to know about her.
Under no circumstances are we to forget when she faced down a squad of goons with automatic weapons, waited until they fired, and sliced every single bullet in half with a straight razor!
The ending of the mind-screwy Episode 4. Everything that happens once the song "Crazy Sunshine" kicks in counts as epic, but Naota finally "swinging the bat" and standing up for himself and Haruko's Big Damn Heroes moment are the kickers.
Everything in the Crazy Sunshine sequence syncs up so perfectly it might as well be a music video.
When Canti first powers up by eating Naota, and then effortlessly beats the enemy robot that had been kicking her and Haruko's ass for the entire fight scene prior, all while Little Busters plays in the background. Hell. Yeah.