Try this WiFi Shield V2.2 for Arduino (802.11 b/g/n) - DFRobot
It uses a mature WizFi210 chip. It provides the bridging from TTL serial port communication to IEEE802.11b/g/n wireless communication. So any device with TTL serial ports can easily be connected with this WIFI module and controlled and managed remotely through a wireless network. Different kinds of communication protocols and encryption algorithms are integrated with the module. The Arduino architecture enables you to easily integrate this module into any Arduino based project.