We took our 5 year old daughter to Tangled and we all absolutely loved it. The animation was amazing! Each strand of hair, each leaf was breath-taking. The story was great and it was nice that a typical wedding wasn't the focus of the end of the movie. Mother Gothel was a perfect passive-aggressive, evil character without being too scary.
The ONLY thing I really didn't like was when she told Rapunzel she was getting "chubby" in one of the songs. I don't think it's appropriate to teach children that being "chubby" (which she clearly is not) is a bad thing. That was disappointing and something that could stick in some kids' minds - especially if they are heavier than their peers.
Otherwise... the songs were great. The story never lagged. There were surprising parts. Overall, it kept us wanting more. So much so, that I wouldn't mind paying the money to see it in the theater again. This will definitely be one we buy when it comes on DVD.