Inspired by the linked XKCD. Using 60% instead of 50% because that's an easy filter to apply on rottentomatoes.
I'll go first: I think "Sherlock Holmes: A game of Shadows" was awesome, from the plot to the characters ,and especially how they used screen-play to highlight how Sherlocks head works in these absurd ways.
That last scene when he gives Kate Beckinsale a burial, and he looks up into the sky and sees her there smiling down at him with a tear in her eye and all that. It was painfully cliche. Lol
That was just the most egregious example I could come up with if the top of my head. Gonna rewatch it and look for more "oof" moments. More than anything, it's that it was a product of its time. Especially with Underworld having come out and inspiring the whole "vampire versus werewolves" mythos in the mainstream.