Villainous awesome: Ommadon leaving the council of the Great Antiquity on Bryagh's neck, swearing on his red crown to his brothers that he will carry out his nefarious projects for humanity, pointing his sword at the sky to catch a red lightning to teleport himself and Bryagh away.
Sir Orrin's first battle against Bryagh, to save the egg that hatched Gorbash. It ends with the knight using his gauntlet and Bryagh's mouth's electrostatics to ignite the dragon's inner gas. It took seven years to recover.
When the wolf Aragh first appears and manages to single handedly save Sir Orrin and Peter from the Sandmirks' Brown Note. All by running through the countless horde to get to their queen. Killing her by throwing her off a cliff, along with himself! He survives of course (mostly because he's technically dead at the moment), but it was still an awesome scene.
Peter (in the dragon body of Gorbash) and Smrgol battling the Ogre of Gormley Keep. Peter has no combat experience, charges like a fool and is quickly overwhelmed, and it's up to the old Smrgol to defeat the monstrous gatekeeper at the cost of his life.
No-nonsense Real World author Peter Dickinson has been trapped in a fantasy world for quite some time (in the body of a dragon no less), forced into a quest to defeat the Big Bad wizard, Ommadon (voiced by Darth Vader / Thulsa Doom himself, James Earl Jones). Just when it seems the evil wizard has defeated the heroic band and all hope is lost, Peter (in mortal form) appears before him, polishing his glasses nonchalantly. While Ommadon transforms into a Hydra and attempts to intimidate him with threats of Biblical feats of magic, Peter defiantly refutes all magic as illogical and impossible. For every incantation Ommadon recites, Peter literally talks him to death, countering with proven scientific facts, eventually having the Red Wizard desperate and on the ropes: