The song is awesome. Very day-glo, techno pop with lyrics so blatant in their meaning that it borders on parody.
The trailers really want you to think "awesome" all day long. They repeat it ad nauseum.
At the beginning of the movie, Emmet thinks everything is AWESOME! Even coffee from a corporate food chain that costs $37!
Metalbeard is awesome indeed! His beard is METAL! His body fell apart thanks to Lord Business, leaving his head (and organs) as the only part of him that wasn't lost, so he threw together a bigger, stronger body for himself out of misc things like chains, huge hands, and a treasure chest on his actual chest. He even made an arm out of a shark!
A good part of the plot is Emmet realizing things aren't as awesome as he thought (President Business rules this toy world like a dictator in a first-world country), and that he likewise isn't awesome at all! But the whole prospect of that can still be AWESOME!!!
He hops out just to turn Bad Cop's aircraft into a baby carriage, and then swiftly hops back into the Batwing.
Batman:Police to meet you Bad Cop.
Bad Cop: Batman! The pleasure is all spine!
Batman: Guess what, yeah big dumb baby? Your car is now a baby carriage!
The scene where Emmet touches the Piece of Resistance is filled with a sense of awe. It's at that moment when someone ordinary becomes someone extraordinary.
While the rest of the film is definitely awesome the climactic plot revelation where you realize just where and how the film is taking place goes a step beyond this. Turns out the entire film was just a played out fantasy by a young boy Finn and his over bearing father in their study. But what makes it beyond awesome from anything up to the film thus far, is how the film becomes a direct Allegory Adventure for them, from everything- the use of KraGle/KrazyGlue on bricks to President Business wanting perfect control. Thus, when the compromise between Finn and his dad is reached, you see through a brilliant montage how it affects the rest of the Lego world. There's a reason this film is getting so much praise from A.O. Scott and Michael Philips.
Benny has spent the whole movie trying to build a spaceship and then having to deconstruct it when he realizes it isn't needed. When the crew finally needs him to build a spaceship, Benny proceeds to construct one completely out of an 80s-esque broadcasting station, and goes on a massive rampage while sporadically yelling out "SPACESHIP!" while crashing through a good chunk of the scenery in the movie up to this point.
Related to that, Batman stealing the hyperdrive from the Falcon and returning less than a minute after he left.
Emmet having his first creative breakthrough during the chase in the Wild West. He's in an urgent situation with a piece of the wheel in his hand and he's ordered to attach it to something round. So he attaches the wheel to his own head and hangs off the wagon as a human axle.
Emmet, stuck in the real world, under his own power somehow is able to move himself, thus catching Finn's attention and return to his real world with the powers of the Master Builder.
Emmet's smart inference that he should get the "smaller creature's" attention if he has a chance of getting out and saving the world. He has really been paying attention to the humans.
He then uses his newfound power to build a Simple Yet Awesome giant mech out of construction equipment and go on a rampage, knocking hordes of Micromanagers out of the sky and saving the other Master Builders.
Even more awesome in the video game, because Superman is the second player.
In the end, how is everything healed? Through Finn and Emmet explaining that Lord Business can be special just by helping out, and by showing how everyone can create and be special. No violence, no wrecking stuff.
Just before that, when Emmet confronts Lord Business. He literally storms into Business's control room, and dishes out kung-fu moves that would make Batman jealous!
Phil and Chris, and everyone involved with the movie, are awesome. They managed to do something people decades ago thought was impossible - produce a Hollywood feature film nearly entirely with LEGO characters in a LEGO world that isn't anything like the lower-quality TV specials or series, and make it excellent. And the movie made more than its budget in three days. And became the highest-ranked animated film on Rotten Tomatoes since Toy Story 3.
... Finn is awesome. He basically wrote an entire story worthy of a home-made Hollywood action/adventure while playing pretend with his father's LEGO collection! His dad was right to encourage his creativity in the end, because we have ourselves a possible future Orson Welles here! Not to mention all his cool LEGO designs.
Wyldstyle, Emmet and Vitruvius escaping the robot police in the Old West with a hang glider, dodging thousands of laser shots.
The scene where Emmet takes out a huge army of police robots in cars, helicopters and on motorbikes trying to kill him on a highway with Car Fu. Well, Motorcycle Fu, but it's still awesome. Even though he wasn't even intending to in the first place and simply trying to master the controls, as he never drove one before.
"DON'T FORGET US, MASTER BUILDERS!" Lincoln has never looked so utterly Badass before. Nor Shakespeare. Or Gandalf. But in that scene, they do.
The fact the animators manage to do the impossible by taking Lego minifigs, miniature toy figures extremely limited in joints, movements, and anatomy (claws for hands, two dots and a line for a face, no knees), and somehow making them move so smoothly and naturally in their own world while conveying every little emotion and personality on faces that normally are nondescript and exactly alike, and even using that as a major aspect of the main character, is an accomplishment that needs to be acknowledged here.
There are several nods to the fandom and LEGO Genius Bonus moments. Johnny Thunder's brief appearance made fans rejoice, and better yet, LEGO released an updated Johnny Thunder minifigure in the second wave of sets for the movie!