I was impressed with the stunning visuals of Asgard. I loved the city of Asgard, as it is seen in this movie.One of the most beautiful sights, is when it shows the stars and nebulas over the city of Asgard, the colours of the cosmic dust... That sky was quite impressive. All the special effects were well made, and the 3D was nicely done.
As for characters, Tom Hiddleston as Loki really wins the day with the performance he gives, and I expect him to return for the sequel. The whole cast is good, and the female audience will appreciate Chris Hemworth (Thor). The rest of the cast is also impressive: Anthony Hopkins as Odin, Natalie Portman as Jane Foster... There is not much that you can say about actors of that caliber.
The story is more than enjoyable and interesting, despite being predictable. It had the right dose of humour, at the right places, and at no point did it become boring. I also liked the fact that there was no melodrama, despite there being a love story in there. In short, the script was solid, without any holes in the story, or becoming boring to the viewers.
THOR is one of the best fantasy movies of the last couple of years. I enjoyed it, I had fun with it, I forgot myself with this movie. What else can someone ask from an action movie?