Bernie certainly deserves a mention for being able to hold his own against the new, insanely powerful, state of the art Gundam for at least a few minutes, despite being only an inexperienced rookie in a battered, mass-produced Zaku. Of course he ends up dying a tragic, horrible death, leading into what can be seen as a subversion of pretty much everything this trope is about.
One could argue that his death is both an awesome moment and a Tear Jerker.
It's the fact he doesn't give up even at the end. Haman even goes on to remark he was stronger than she ever gave him credit for.
And before this moment? He was routing Ple/Puru Two in the Quin Mantha (A giant mech with powerful weapons in a custom mook suit. To say he took levels in badass from his Joke Character days is a pretty big understatement. Especially considering later on the ZZ Gundam itself could barely scratch the Quin Mantha, while the Quin Mantha one shotted two Gundams.
What about Judau having bombs strapped to the ZZ Gundam, and then strapping grenades to himself? And then, he forces his way into the Neo Zeon flagship with them.
Then there's his wrath at his little sister being grazed with a bullet. He goes from openly not caring anything about Newtypes to manifesting a skyscraper-sized demonic avatar visible to every Newtype in the city. It is so terrifying that Haman Karn, who was responsible for hurting Leina and is less than ten feet away from him, throws dignity and composure to the wind and runs back to her room as fast as she can, essentially reduced to a terrified little girl desperately trying to escape from a scary monster.
In the final episode, during his duel against Haman, Judau reactivates the disabled Double Zeta by channeling the strength of the good men and women from the original series, Zeta Gundam, and ZZ, including Elpeo Puru, Lalah Sune, Four Murasame, Katz Kobayashi, Sarah Zabiarov, and lastly Kamille Bidan. He then unleashes a tremendous Wave Motion Gun blast on Haman before their duel ends with a Single-Stroke Battle exchange. This leads to a Crowning Moment of Heartwarming, where Haman admits defeat as Judau asks why she didn't use as many funnels as she could've. Haman scoffs that they were conducting a duel and it wouldn't be fair, and dies with a smile on her face anyways, glad she came back if only to meet Judau.
Judau punching Bright Noah at the end of the series. Awesome for Judau for enacting revenge for all those Brightslaps that Bright handed out over the course of three series. Awesome for Bright because it let Judau vent all his frustrations.
As long as we're talking about Judau punching people we can't forget when he punched out that obnoxious prick Wong Lee. Made even more awesome by the way it punishes Wong for the way he beat up Kamille back in Zeta.
"I am Mashymre Celo, Zeon commander!" "I am Judau Ashta...." glances to the left and right "...currently skipping school!" ...although this may be a Crowning Moment of Funny, but let's just say it belongs here.
The Battle of Dublin is just an awesome sequence because of the way it establishes atmosphere, and the way it just keeps escalating the threats the characters face. The Neo Zeon are attacking Dublin! With a Colony Drop! And they're sending in mobile suits to stop everyone from escaping. And one of them is the Psyco Gundam Mark II!
The most notable one is in the ending. After defeating Char in battle, Amuro tries to push back the Colony Drop Char was planning throughout the entire movie. Physically. Although this would be a suitable one for Amuro, it's even more of one for the series' mooks. As Amuro struggles to push back to Axis asteroid, which would send the Earth into a new ice age, the rank and file soldiers from both sides of the war charge in and help push the asteroid back, despite Amuro's pleas for them to go and save themselves, due to the fact that atmospheric re-entry would destroy their mobile suits. They gladly continue pushing back anyway, the soldiers of each side sacrificing themselves to save the earth, even as they explode left and right. This troper never thought he'd shed Manly Tears for faceless, nameless mecha mooks like that.
My favorite was the second time Amuro faced the Zeon Ace Pilot Gyunei Guss, except this time it was a fair fight and Amuro took him out with barely breaking stride. Letting go of the shield in the middle of a smoke cloud and then flanking him was just one of those clever moves Amuro was known for.
For this troper, Amuro jumping out of a car to crash-tackle a horse-riding Char is the scene that sticks in his mind for the movie.
The final battle between Loran Cehack and Gym Ghingnham at the end of the series, not the final battle between Turn A and Turn X Gundams but these two. After the two Gundams are locked in each others Moonlit Butterfly attack Gym throws Loran a sword and asks him if he ever used one before, Loran replies that he did once and then proceeds to unleash Tranquil Fury upon Gym until Gym is swallowed by the twin Moonlit Butterflies.
Gundam Nadleeh's first on-screen appearance. After jettisoning Virtue's armor with enough force to send his attackers flying, Nadleeh grabs Virtue's Shoulder Cannons, crosses its arms in front of itself and fires a single shot from each over the other shoulder. That single shot instakills all six Tierens who were holding it down. Even resident Colonel Badass Sergei Smirnov was sufficiently intimidated by it to order a retreat... for the three remaining members of his squad. This incident cemented that if Tieria switches over to Nadleeh, he's serious; too bad he screwed it up by bawling his eyes out over how he wasn't supposed to reveal Nadleeh this early in the plan, breaking down to the point he stopped using masculine pronouns altogether.
Setsuna's final battle in the first season. He had just beaten the Big Bad of the first season, his Gundam is damaged and he's exhausted. Then out of nowhere Graham Aker shows up in his custom Flag... except that his Flag has a GN Drive tacked on it and is toting a beam saber! The two summarily proceed to tear each other's mobile suit to pieces in a short but very violent battle, trading Motive Rants back and forth all the while.
Allelujah never really liked when Hallelujah took over his body and went to kill stuff. So when Allelujah's Gundam is heavily damaged with the enemy actively searching the area for him, what do they do? They team up and temporarily merge, of course! We get to witness a hyper-awesome two-on-one Curbstomp Battle where Doublelujah utterly owns Soma and Sergeiat the same time.
...which didn't prevent him from getting his own moment right afterwards when Wang Liu Mei tried taunting her: He backhanded her so hard she fell off her feet. Granted, she had it coming for quite a while but still.
Wang: "What's the matter? You seem rather unsettled-" THWACK!
Ribbons: "Shut up, you greedy little bitch."
Possibly the greatest moments of the second season were in the 17th episode.
First, Celestial Being got the 00 Gundam into space with a two-stage acceleration by flying vertically upwards in the Ptolemaios and using the momentum to launch the 00 and the 0-Raiser, the two combining in mid-air and flying forth on their own. In the upper atmosphere, the Empruss ambushed and almost killed them... then the 00-Raiser went Trans-Am and not only blew the Empruss away with a single shot but used the particle beam as a gigantic beam saber hundreds of kilometers long. The enemy's reaction was simply priceless when the beam came out of nowhere, turning into a Hope Spot as it closely missed their Kill Sat... then the beam started sweeping.
When the Memento Mori's dying shot hit the orbital elevator, the good guys called out to everyone on the battlefield that the fragments of the elevator are going to hit heavily populated areas and kill millions. Cue Celestial Being, Katharon, the Federation army and even A-LAWS deciding to shoot the falling debris instead of each other with what is probably the largest furball of mobile suits gathered at one time in the whole series. Not just Gundams and A-LAWS' state-of-the-art mobile suits but even obsolete mookslike Flags and Tierens from the first season, all working together to save those lives.
In an early episode of the second season, Setsuna is swooping down on an enemy aircraft carrier with intent to kill... then out of nowhere appears Graham Aker and crash-tackles Setsuna's Gundam in mid-air.
The final fight of the series: Setsuna piloting the Exia versus Ribbons piloting the 0 Gundam. Why is it awesome? Just consider who is Ribbons' seiyuu and take a look at his machine◊. Looks familiar? Damn right it does; it's a goddamn RX-78! It is simultaneously a touching homage to the original Mobile Suit Gundam and (through Setsuna's victory) a symbolic Passing the Torch to the newer Gundam series.
Then came The Movie, chock-full of awesome moments.
Quite early in the movie, Allelujah and Marie are being chased by ELS-controlled vehicles. Upon realizing that they're going after Marie, Hallelujah jacks Allelujah's body to act as bait, evading the rogue vehicles with spectacular application of Le Parkour.
One can be summed up thus: what's better than Doublelujah curbstomping stuff in a Gundam? Doublelujah and Soma/Marie co-piloting a Gundam. That's right, the two most successful results of the HRL's Super Soldier project fighting side by side in a Battle Couple!
Graham, his mobile suit on the verge of being completely overtaken by ELS, gives Setsuna a Rousing Speech and deliberately crashes into the ELS structure Setsuna was up until that point unsuccessfully trying to infiltrate before going boom, tearing a sizable hole into the thing and allowing Setsuna to proceed. Despite Graham trying to kill him for two whole seasons, Setsuna is visibly saddened by his passing.
"This is not death! IT'S FOR HUMANITY TO LIVE ON!!!"
Andrei chases down an ELS that got past the final defense line and despite having far too few firepower to destroy it, he attacks it in melee and blows himself up along with his whole squad to stop it from reaching Earth. What is especially touching is that right before his death, we see a brief shot of his dead parents (whose sakes Andrei is a soldier for) smiling at him.