In Up Your Arsenal, as Ratchet approaches the final boss arena he is suddenly confronted by several of the toughest robo-mooks the game can throw at him. When it looks like these guys might finish him off before he can even get to the boss... the usually cowardly Galactic Rangers warp in and start blasting the mooks apart. "LET 'EM HAVE IT, RANGERS!" "YEAH! YOU WANT SOME A' THIS?!"
From earlier in the game. Our disposable mooks this time around are the Tyhrranoids, a race of small brained round monsters with googly eyes, who are too stupid to realise that their bosses master plan involves killing them all right from the get-go. And then you go on to assault their home planet of Tyhrranosis and meet the Momma Tyhrranoid, who, despite the name, is about thirty feet tall, has about ten rows of sharp teeth, and has a freakin' rocket launching turret strapped onto her head! Suddenly there is something about the 'Noids which is genuinely threatening.
Also from UYA, there's the bit where Ratchet and Clank encounter Nefarious' Bio-bliterator. Ratchet comments that his biggest gun wouldn't even be able to dent the weapon. Clank responds by indicating a huge anti-spacecraft turret: "Then we shall just have to find a bigger gun." When the pair get inside the turret, Clank hacks the weapon as Nefarious rants at him over a monitor:
Clank: After all those holo-films, there is one thing you should know by now: Do not mess with Agent Clank! (BOOM!)
A Crack in Time has Ratchet's midair rescue of a deactivated Clank
There's also Clank's fight with the Hypersonic Brainwave Scrambler. It's one of the few boss fights in the entire series where Clank does NOT turn into Giant Clank...and yet he still scraps the Brainwave Scrambler.
Clank: One Hypersonic Brainwave Scrambler...scrambled. *Giggles*
This is more of a technical awesome. Yet when you started the actual game play for Ratchet and Clank Future: Tools of Destruction, you were impressed by the clarity of the backgrounds. More Visual Effects of Awesome than a moment, but it still counts.