What is the strongest move in martial arts?

Answer 1

In terms of raw force generated. The muy thai knee and the turning backside kick have been proven to deliver more pounds per square inch than any other move. Also, moves with at least one foot anchored to the ground will almost always be stronger than their flying counterparts. Hope this helped.

An alternate point of view is to answer the question not in terms of "raw force generated," but in terms of what the move does to the human body. Most eye gouges are serious enough for a person to bleed to death from the eye gouge. A classical karate chop to the neck can sever someone's spinal cord, and usually this results in death because the breakage is serious enough to paralyse the lungs and heart. Also, crushing the windpipe with an extended knuckle fist or a sideways karate chop can cause a person to choke to death. These are the three primary moves that would be classified as "dim mak" strikes, or in Western language, moves that cause death in a single blow.