I wanted to see this movie because of my combined love for the actors: Gerard Butler, Jay Baruchel, Craig Ferguson and America Ferrara. What I discovered was a truly fun, delightful, heartfelt action movie for both kids and adults.
I was a bit skeptical about the animation because of what I saw from the commercials. However, one look at Stoick's (Gerard Butler's) beard and I was won over - it's a very emotive beard.
Jay Baruchel plays Hiccup, possibly the worst Viking ever, who really just wants to fit in with the rest of his tribe. In order to gain acceptance, he has to kill a dragon. What follows is just plain AWESOME. The action is breathtaking. The characters are charming, believable and very human.
I'm not gonna say too much more 'cause I don't want to play it up too much or give anything away but if you want a movie with a good story and a good heart -- Dragon's a safe bet.