Thor: Turn Off the Dark
Excluding made-for-TV movies and licensed properties not directly under their control (e.g. Ghost Rider, Daredevil, F4ntastic, etc.), this may be the weakest Marvel film to date.
On paper it sounds like a great idea, a Thor movie largely set in Asgard, taking advantage of the amazing scenery possibilities, seasoned Shakespearean actors like Idris Elba, Sir Anthony Hopkins, and especially Tom Hiddleston reprising his delightfully engaging Loki character. Add to that the Jack Kirby-inspired take on the Asgardians as not gods but a highly advanced race, and it seems like it would be one of the best Marvel films so far.
Except that the execution is botched. The basic plot goes something like this, an alien race, sometimes referred to as Dark Elves use a psudoscientific/pseudomystical force called the aether (which becomes contained within the body of Thor's beau Jane Foster), and when the nine realms align, they're going to use it to plunge all the realms back into darkness - or something like that.
But it comes off as a generic space opera (ala The Chronicles of Riddick, etc.), but without that Marvel charm seen in Guardians of the Galaxy. Long-awaited characters from the comics such as the Lady Sif, are introduced, only to be thereafter ignored. Nor is that time spent further developing any of the major characters, who pretty much take a backseat to an endless parade of visual effects shots. Though it is action packed, without a reason to care about the characters, that action seems dull and pointless.
I agree that this is a step in the right direction for the Thor franchise (more emphasis on Asgard and Norse mythology) but it's a shame it comes across as so written and directed by committee.
Now that doesn't mean the film will be thoroughly unenjoyable or awful, the uncritical eye might even find entertainment value in it. But really one can get that level of spectacle from Transformers or a hundred other big budget effects films. Marvel has hitherto managed a level of quality to which Thor: The Dark World fails to achieve.