The sight of seeing Magical Girls (well, actually more very-high tech than magic, but still counts) and the military working in tandem to defeat the Alone.
Especially seeing them ride into battle on top of fighter jets.
Lt. Amagi kamikaze-ing an Alone laser beam in the first episode, saving Aoi's plane while managing to eject from her own. Damn, girl, that took some balls.
During episode eight, the girls minus Akane, who is comatose thanks to the very Alone they're going to fight, show up at the rallying NDF operation, despite knowing the long odds of fighting an ever-strengthening Alone. The plan gets under way, and at a crucial moment, Aoi is aided by Akane's boomerang, brought along for sentimental reasons, acting as a jet booster allowing her to strike the finishing blow, jamming a powerful explosive into the Alone's gut and saving her friends from imminent danger.
In the final episode, Akane is pitted against an Eldritch Abomination powerful enough to obliterate not just the world, but the entire universe. How does she defeat it? By fusing with Rei, transcending the limits of the Vivid System, skydiving straight towards it from the upper atmosphere, and punching it right in the face with the Power of Creation itself. Now that is awesome.