Overall, I liked it. Good action in the scenes on Asgard and battling the frost giants. Same with the battle between Thor and the Destroyer. It was nice to see a Superman-level character in a movie do something other than lift things and stalk his ex.
More CGI than I prefer but that's to be expected these days.
Most of the actors were good. The one exception: Kat Dennings' character was too annoying, especially the way she wore baggy loose fitting tops throughout the movie. Also, while I realize it was necessitated by the plot, there was nothing in the movie to explain why Thor would be interested in Foster and not (as often the case in the comics) Sif.
Enjoyed some of the subtle nods to Marvel history: the mention of a Gamma-ray expert who got involved with SHIELD and was never seen again, the SHIELD agent assuming the Destroyer was "one of Stark's" inventions, calling Thor "Don" as a fake name to SHIELD, etc.
The post-credits scene with Fury was the weakest one of the series so far, but I guess that's going to be expected since they've now lined up everything except Cap for the Avengers movie.