I'm not the biggest fan of paying for Xbox LIVE (although I reluctantly do it annually), but if you're going to do it, at least do it for cheaper. Right now, Amazon.com is listing Xbox LIVE 12-Month Gold Membership cards for an incredibly random price of $46.40, or 23% off the regular
rip-off retail price.
You need Xbox LIVE Gold to do things like play online, watch Hulu and Netflix, and more.
There's not much more I can say, other than go take advantage of the savings while you can.