I absolutely LOVED it and agree with the 5 star review that comicvine gave it, but it wasn't without its flaws. The biggest which is that you could tell that it was just a LITTLE too big for itself. Its VERY obvious some scenes were cut to make the movie a more manageable length.
It seems that Thor suffered the most with this problem. He shows up out of nowhere (which was cool though), when last we heard he couldnt come back to Earth because of the destruction of the bifrost. Its really never explained what the hell happened to Loki after Thor, and how he ended up in deep space, or how he even survived. The significance of Thor's costume was never explained, and why he didnt fully suit up until the end. Thor also apparently knew all about Loki's plans including his alliance with his "army" even going so far as to know the name of their species, but HOW he knew this is anybodies guess. Theres also the whole inconsistency with the end of Thor, and The Avengers with Dr Selvig apparently being possessed at the end of Thor, but apparently that wasnt the case since we never see anything come from it or anybody mention it.
Other than that the movie was awesome especially the action scenes which were AMAZING. I really hope that we see a proper directors cut that can expalin some of these things. I heard that it was originally going to be around 3 hrs long! I would LOVE to see that movie.