In general, I tend to think that animated movies are ones that I thought I wouldn't like because of the concepts of being a kids movie. I find that I usually am surprised about the message and how well it is portrayed.
I liked 27 dresses, when I thought that it was going to be a typical chick flick. I think we went to see something that was sold out and 27 Dresses wasn't. Fantastic Four was another one - yeah laugh at me, but I do find it fun. I had heard that Mama Mia was awful, but I totally enjoyed it.
I also find that I am generally unimpressed with movies that are supposed to be good or on the cutting edge. A billion years ago, "Clockwork Orange" was to be the cutting edge absolutely must see movie. I found it disgusting and the beginning of violent movies for the sake of violence and nothing else. Sideways, Alferd Hichcock movies, other classics - I didn't like.