I'm kind of a dull person to watch movies with, since I really don't get too emotionally drawn into a movie. But I have noticed that the one thing that seem to provoke my feelings the most is the unexpected. When someone in a movie is sick and it's obvious he's going to die sooner or later, I rarely find myself saddened when he dies. But in a movie where the story seems rather predictable, and then suddenly one of the likable characters dies I find myself shocked and saddened by this new turn of events.
Or, to look at it from the other side of the coin, a gag can become much funnier when it's unexpected, such as in Aardman's short Aardman where a guy dressed up as a superhero walks up to what looks like a hole in the ground. He walks over the hole and nothing happens, but when he gets a couple steps past it, he falls through the ground, turning somthing that would have been a cliche into somthing that surpises the audience.
Of course, you can't use the unexpected too much, because it will soon become the expected. For instances, in M. Night Shyamalan's movies, people have come to expect a big twist in the end and often are disappointed because they wanted a epic twist when it was just a good one. Try doing something unexpected in your animations. If you do it right, you'll get some good reactions.
To illustrate my point, check out the video below.