Thor: The Dark World 6.8/10. It's not bad, but just not quite 7 (which is what I think the stand alone Marvel movies are).
There's a lot more action in this one. It ended up being more funny than a dark epic, but still a good fun Marvel movie. Loki is gold.
I wish they had more of Sif and the 3 warriors, but w/ so many characters on top of Thor/Loki (Malekith, Odin, Jane, Darcy, Selvig, Heimdall, Frigga, dark elf henchmen) I could see why they were passed over a bit.
Overall just turn your brain off and go to Asgard. Lots of surprises. Oh and be sure to stay ALL the way toward the end credits...there's 2 scenes. One midway, one after all the credits show.