No. 1: Costume Design
Now to be fair some of the costume design in TDK was pretty good, but some made very little sense. For example, minor decisions such as Catwoman's hair not being tied up. Long loose hair hardly seems practical for a cat burglar who we are to assume regularly crawls through laser security systems. Also major stand outs like the lack of effort on Scarecrow and Bane's massively distracting mask, but more on him later. On the other hand the costume design for BvS was phenomenal. By leaps and bounds the best live action look for Superman we've ever gotten, Gal Gadot seems like she was born to dawn the Wonder Woman armor thanks in part to how amazing it looks, and the Batsuit was the perfect blend of comic book accuracy and real world practicality with its layered armor, voice synthesizer, and a light flexible quality which didn't seem to hinder Batman's movement. Which brings me to the next point.