Allura dropping a superpowered Lotor and then opening fire on him. He probably would be dead if not for being powered by Voltron's Kryptonite.
Keith decapitates a Robeast during a crash landing from space! Pretty funny as well.
Any time a new formation is revealed.
The first time Voltron formed in the opening episode near the end.
On a similar note, but on the other side of the fight, the Predator Robeast.
The opening montage in the first episode has a scene where evil King Lotor raises his blade and yells at Voltron.
An Evil Moment of Awesome comes when Lotor, superpowered by Haggarium power-up, pins down Voltron and cuts the lions in half. ALL of the lions. If not for Vince, that would have been Game Over for Voltron.
Allura beating up on Wade's forces when captured and outright stating that she could have escaped sooner if she wasn't waiting on Larmina.
From the same episode, Allura "forming the leg" and kicking Wade's giant robot through the force field seperating her from the rest of the Force.
The sequence where Keith frees the Black Lion while Allura welcomes Lance, Vince, and Daniel to the Castle of Lions. It felt like coming back home.
Episode 13 FINALLY uses the ORIGINAL Voltron theme music when Voltron was forming up. Completely made the episode worth while.
A smaller moment of awesome is Pidge finally revealing his Voltcom weapon, and kicking some ass with it too.
#14 finally features the premiere of Green Center! Pidge dubs it Tech-ninja Voltron, and it definitely lives up to the name!
"Ghost in the Lion". About everything Sven does; from defeating the other members of the Voltron Force when the odds were 4 against 1, to fighting Lotor one-on-one as the ice beneath them breaks apart and win causing Lotor's third death.
Daniel sums up a huge moment of awesome, with one simple statement.
Daniel: The original Voltron Force rides again!
From the same episode, Allura secretly providing Sven the means to escape and save the Voltron Force while pretending to go along with Lotor and Maahox's plan and letting them take her and Sven's son prisoner.
Keith bouncing off of Dradin in sunglasses, bumping music, and a pimped out Black Lion.
Keith's mere presence being able to frighten off a bunch of young street punks who had the balls to steal the Black Lion.
Which is, of course, followed by Daniel getting his pilot spot in the Black Lion.
Voltron VS Spider Ro Beast Lotor. Epic fight was epic.
Not to mention Mahoxx finally snuffing out Lotor.
Pretty much all of "Black".
Haggar gets one even if she is dead. Apparently, after her death her body somehow became a quasar that produces haggarium, material that can resurrect the dead, give superpowers to others and act as Kryptonite Factor to Voltron.