I watched Rio with my daughter a couple of weekends ago, and enjoyed it quite a bit more than expected.
I went into not really knowing anything about it, beyond being about birds.
Before getting too much into the specifics, it was kind of weird having Fox doing a movie about humans interfering with the environment, given that it seems to be Fox "News'" mission to discredit global warming.
Leaving that aside, the musical interludes were very well done. I especially liked the use of samba and bossa nova, as I'm very fond of both styles (although I don't think I could listen to either with huge frequency), and samba is definitely great dance music (though I've probably forgotten all the steps I used to know; it's been a while).
And the concept of the movie is also great; taking the brazilian bird to Minnesota, and having him grow up a geek. His initial attempts to learn to fly were hilarious.
I liked, too, the relationship between the two main humans. Predicatble, and not deep; in fact, pretty much playing to stereotypes, but funny.
In fact, the whole movie was pretty predictable, but still very enjoyable.
Jemaine Clement did a wonderful Scar-turn as the bad guy; he was excellent.
I liked it pretty much from beginning to end; just lots of fun to watch.