Just a summary from all of the above, BoA is the best singer-dancer to me because:
1- she can both sing & dance at the same time, and pretty darn good at both!!
2- She is a versatile dancer. She can do all kind of dancing from sexy to aggressive.
3- Like Cori said, she put a special 'UMPH" in her dancing. Other people can cover her moves, but they can never cover that factor BoA puts in the dancing, from the move of the body, to the expression on her face, it's just unique & special.
One thing I really like about BoA dance is that it just 'enough'. Not too sexy, not too covered up, not too weak, not too strong, not too slow not fast. Just perfectly enough. (if it even makes sense to you ^^" )
Oh, almost forgot, some more of my favorite of all times Epic!
that over the top performance has got to be one of my most favorite performances from BoA she did outstanding. I heard that she was so exhausted after performing she fainted )): . BoA's dancing is very crisp and clear with enough power to make you go wow. You cant not look at her when she dances because she has that attitude and "swag" that tells people, "Yes I'm Queen, I own the stage and what?" And for the ppl u mentioned like Hyo and Min , they are really good dancers but they cant sing beautifully like BoA at the same time.