I don't know about the best wigs, but the worst ones I know of are the Jon Renau wigs and the worst place to buy them at is Voguewigs.com.
On the Jon Renau wig, the front of the hairline curls up, exposing the underside of the lace making the wig look ridiculously fake. Aside from that, it's an average wig as far as synthetics go.
The worst place to buy one is voguewigs.com. They won't post the negative review I gave the Jon Renau wig because it would lower its five star rating. They only publish the positive reviews in a deceptive marketing scheme designed to fool cancer victims and other hair loss sufferers into thinking the wigs are better than what they actually are. Their return policy is as bad as their wigs.
I complained to both companies, but neither cares. Neither Jon Renau nor voguewigs.com stands behind their products.