My boys (8 and 5 yrs old) and I recently saw the Lego movie. We all loved it. It's one of the best films I've seen this year so far. Will Ferrell is an impressive actor, not just in the over-the-top baddie segments, but also in more subtle moments.
The story is basically the Matrix in LEGO. As a fan of both the Matrix and LEGO, this seems to me a good combination. Highly recommended.