I love the Xbox 360 Wireless Networking Adapter (802.11A, 802.11b,802.11g) , but I'm apparently a minority. Some people dislike it for the price ($99), some people because they don't trust Wi-fi, and some people because they just don't want to be locked in to a Microsoft device. With that in Mind let me recommend some alternatives.  85 MBPS POWERLINE 4-PORT ETHERNET ADAPTER:  My Favorite, and something I use even though I have wireless in my house, I prefer it because it doesn't crash, it doesn't drop out, and it also extends 3 additional devices so I can hook up both my Xbox's my Turtle Beach Audiotron, and still have a spare for that second console I'm thinking of getting.  As of posting this was $75 at Fry's and pricegrabber claimed a similar price. HAWKING WIRELESS-G HWR54G 802.11G WIRELESS ACCESS POINT & ROUTER W/4-PORT SWITCH:  This is a great solution for less than $50.  Set it up to talk to your existing WiFi, and it then offers 4 ports of wired connectivity.  Just plug in your Xbox, PS3, Wii, and Tivo and your home theatre is "unWired" for the Internet. Internet Connection Sharing:  This is the Cheapest if least convenient. Despite the picture, this works just as well with the PC connected to WiFi.  This is how we did the Xbox Live over Google WiFi.ICS essentially lets you use your PC like a router, which is definitely convenient—but it requires that you turn on your PC when you want to play games on Xbox Live.With all of these solutions the desired result is that when you go into your network settings you see: My network at home my NAT is Closed because I disabled UPNP. The Most Common setting that has bitten me is MTU.  That is the limiting factor for Google Wifi, EVDO, and other "weird" *ahem* ADVANCED way's of connecting your Xbox to Xbox Live. MTU is a setting on your router or gateway that can affect network performance; the MTU diagnostic test will tell you if your router or gateway's MTU is too small. The MTU determines the largest datagram (a self-contained packet of information) that an IP interface can transmit. The larger the permissible datagram for your router or gateway, the faster the data throughput. Thus: the larger the datagram, the better the gaming. Xbox Live requires a minimum MTU setting of 1364, so your router or gateway's MTU must be greater than or equal to 1365. If it's less than 1365 you won't be able to connect to Xbox Live. If your console does not pass this test, you will not be able to sign in to Xbox Live. In this case, change the MTU setting on your router or gateway to a value of 1365 or greater (see the documentation that came with your device for details).