The story of the forgettable 'everyman' Emmett who falls into greatness - literally by finding the Piece of Resistance as foretold by the completely made-up prophecy that would save the world from President Bizness much like Frodo Baggins in 'Lord of the Rings'. Unlike Frodo, however even Emmett's teammates are unconvinced of his specialness and bemoan their fate being shackled to such a loser who lucked into being 'The Special'.
Emmett's a happy, rules-following guy but over the course of the adventure, he's forced to realize that no one really knows him, he's just another face in the crowd. His potential love interest Wild Style cannons between bolstering Emmett's ego, swallowing her bitterness at not being 'The Special' and really trying to get her boyfriend Batman to commit to, well, anything. Along with the rest of the Justice League, a blind wizard and a creature known only as 'Uni-Kitty', they try to formulate a plan to infiltrate President Bizness's fortress to stop his evil scheme to preserve perfection using the 'kragle'. In the end, it's Emmett's ability to do the mundane that allows them to gain entrance as no one expects...a double decker couch!
The unexpected twist at the end really drove home that the point of LEGOs are not to be built then preserved for eternity but that they are toys and meant to be played with in lots of ways so GEEZ adults, get a grip.
Also, Everything Is Awesome!