Okay, so I could talk about how many laugh out loud moments there are (too many to count, even on a second or third watching), I could talk about the exceptional voice acting by some really big stars (and some cool cameos, i.e. Billie Dee Williams), I could even talk about the really cool visual effects that are more true to the Lego world that any production before it (water, fire, smoke, everything is Lego), but when it comes down to it, a great movie is first and foremost a great story. This great movie, however, is two great stories.
First great story: It's been done where someone is mistaken for a chosen savior/hero/etc. and that's always comical. It's been done where the hero has to look inside himself to discover their inner worth and save the day (usually this happens when the hero's more superficial power is taken away). But I don't think I've ever seen something where we assume the hero is actually a mistake because he has no skills, but then it turns out he is the chosen one specifically because he has no real skills. Then we find out he's not actually really the chosen one because the prophecy was made up. Then the hero saves the day by believing in the prophecy anyways and telling the bad guy it's about him. I mean, seriously, this is a pretty original story. Plenty of less than conventional twists and turns. But, the best part is, it's not even the actually story.
Story number one is completely made up by a kid in the completely unexpected turn in which we realize this is a live action movie, with CGI just standing in for a boy's imagination. The story up to that point was really a metaphor to one of the worst realities that has ever faced the world, people that are meticulous and precise and exact that plan everything and are super organized don't function very well with those that are spontaneous and creative that don't care about details or being perfect. Whether we're more left or more right brained, there are few out there who haven't clashed with someone who leans more strongly the other way. I've seen it in offices and schools and on basketball courts and stages, between husbands and wives and between complete strangers. It seems to be universal that when someone cares about specifics and another person doesn't, they'll clash at some point. Never is this more true, though, than with kids and toys.
There's no doubt that the creators of The Lego Movie had a similar experience to mine when they were little. I had lots and lots of great toys, but few as cherished as my Lego collection. Unfortunately, I shared it with my brother. He grew up to be a computer programmer and I grew up to teach music, so you can imagine we weren't quite on the same page when it came to how important instructions were. He'd build something flawlessly, only to have me take a couple piece from it to build some hodgepodge castle/spy headquarters/car thing. He wasn't super anal about it, but it was frustrating at times as we clashed. In the film, this frustration is taken to a new level as a dad that is meticulous about his Lego creations keeps the vast majority of his collection strictly off limits to his highly imaginative and talented son. When the dad plans to glue his sets together, his son feels like he's destroying all the potential those little bricks have.
The reason I love the story is it spends 90% of the time in this fanciful, magical, impossible to relate with fantasy world. Then, unexpectedly, everything becomes familiar and relate-able and suddenly this fantasy you've been watching is no longer disassociated. More than anything about The Lego Movie, I love that they placed meaning behind a franchise that has always been relatively meaningless. No one expects a great moral lesson or true life experience to be at the heart of a movie starring little plastic men, but Lego Movie changed that forever.
Overall, The Lego Movie is a must have. Absolutely worth owning, whether you have kids or not.