The way Kirk listlessly slumps against the wall when gently pushed. They way they got a dude with an obvious Spanish accent playing an Indian superman. The cardboard sets. The way the superman drops when hit once or twice with a PVC pipe.
I like the self-conscious way Khan folds himself into the corner at the beginning. It's oddly feminine for some reason. Speaking of feminine body language, how about the battered-wife style flinching blink Kirk gives when Khan throws the gun aside. I never watched Star Trek... these two were lovers, right?