this is an awesome movie. i really don't like animated movies generally, but this i think is one of the best. i'm an adult and don't have any kids.
A pretty good animated movie, but I was disappointed at the extent to which the movie dumbed down the books, of which there are now 5 or 6. In the books, Hiccup was even more outcast and physically inept, and the tribe of Vikings had a coming of age ritual of going to the dragon's nesting area and taking a baby dragon to train, with Hiccup accidentally grabbing the least fierce dragon possible, but one with a lot of sarcastic intelligence.
I watched it yesterday in Imax 3D w/ Mrs. Viking. We both enjoyed it, but felt kind of odd at the condition of Hiccup at the end. To be fair, I thought it fit the story, but that the story wasn't quite as kid appropriate as a result.
Just watched it on IMAX and 3D - that was really spectacular. Never read or knew anything about the books, so I can't say anything one way or the other, but it was definitely one of the best movie experiences I've had.