Even WPA2 is vulnerable now, although the hacker has to get between a connected client and the router. There is a good online guide to wireless network security i came across recently, it might help: Home | Wireless network security
Isp supplied I'll beleive and defer to you having not dealt with one of those in a while. I was talking just ones that you can buy at a store or online by yourself.
Secure your wireless network using WPA-PSK2. And as an added security level, disable the option to broadcast your SSID.
MAC address filtering is more of a 'head in the sand' approach to network security. MAC addresses can easily be altered. This is not an effective method for securing your network.