One of the veterans saying "Let's drop some lead on those mother-" before the big guns start firing.
Nagata taking down two alien spaceships by blind firing missiles at where he guesses they'll be. He misses on his first few salvos... and then when he scores the hits it's so sweet.
The John Paul Jones taking down the third alien ship by having two sharpshooters (Hopper and Nagata) blow out its bridge windows, exposing the cripplingly-photosensitive aliens' eyes to the morning sun, blinding them and leaving the ship near-helpless as the JPJ blows it to bits.
Watching the reactivation of the USS Missouri under the hands of the veterans to the music of AC/DC's "Thunderstruck" is majestic.
What makes it even better is that the ship used to portray the Missouri is the actual Missouri, which is a real life museum and, prior to filming, had not sailed in over a decade. The reactivation we see onscreen is her actual reactivation and first voyage in years, crewed entirely by actual veterans.
After destroying what they think is the last of the enemy's ships, our heroes turn to the nebulous shield generator... which then reveals itself to be the biggest warship yet.
Mick overcoming the loss of confidence that came with the loss of his legs, and giving the alien marine an old-fashioned beatdown. Doubles as a Crowning Moment of Heartwarming when he gets his medal. Doubly awesome considering he's an actual amputee who did his own stunts!
At one point we actually see him punch some of the alien's teeth out.
Admiral Shane gets one when the Secretary of Defense presses him to send more craft against the barrier in an effort to get through despite mounting losses from doing so. Shane gives the Sec Def a thorough chewing that ends with this. "You want me to send up another plane? I'll do it the second you come up here and sit your ass in the copilot seat!" *hangup*
There's something to be said on the meta about being able to make little plastic pegs into a badass weapon for the sake of keeping a theme.