The best brand is the one that fits you right, stays on your feet, and doesn't give you weird pains when you dance in them.
I can't tell you which brand is best because everyone's feet are different and everyone has their favorites. Some brands commonly worn by competitors are:
Dance Naturals
Supadance
International
Freed
Diamant
Personally, I've tried Freed, Werner Kern, Supadance, International, Capezio, Dance Naturals, and Diamant. My personal favorite is Diamant. Other people swear by Dance Naturals. Others wear only Supadance. There are literally hundereds of combinations of styles, heel heights, and sizes to choose from. I hate to tell you this, but it took me about seven years to find the best pair for my feet!