Buy 3 Months get 3 Months Free of Xbox Live (Digital Code) $24.99
Newegg

Xbox LIVE 3 Month Gold Membership (Digital Code)
Free Xbox LIVE 3 Month Gold Membership w/purchase
$24.99

Play together with friends in the world's premier gaming community
Get free games to play with friends every month, worth up to $700 a year
Receive exclusive discounts of up to 50 - 75% on games in the Xbox Store
All future Games with Gold titles for Xbox 360 will be playable on Xbox One