There HAS to be enthusiasm. If I want to see a girl who looks bored out of her skull or like she doesn't give a shit, I'll go find my ex-wife.
Skill doesn't really stand alone in my book, but is paired with appearance. Ya know how sometimes it's said of us guys that "it's not the size of the boat, but the motion in the ocean"? Same thing with dancers. She can have all the skill in the world, but if she's not exploiting her best assets, she may not be as appealing as a girl who has less skill but knows how to use what her momma gave her.
Now, a dancer who has enthusiasm, uses what skill she has well, AND is trying to improve her skill -- that's the trifecta! My ATF doesn't think she can stage dance well, but she's working on it. Frankly, I hope she's wrong, b/c if she gets much better, I'm gonna have a coronary.