The best wireless gaming card is none. WiFi is more prone to bandwith fluctuations than Ethernet. If someone's watching YouTube on the same network as you, your WiFi's gonna take a mega hit in comparison to Ethernet, where you'd barely feel a thing.
Someone will probably come and shoot this down but I speak fro experience. I used to game on WiFi with a 450mbps PCI-E 1X card, and my ping was never stable. But running a $2 Ethernet cable to my PC has changed everything.