If you play the Xbox 360 on Xbox live then you know it can get expensive and there are not many real ways you can get an Xbox live gold membership code for free of any kind 3 or 12 month but I'm going to show you a website that really does work and you can even get a code emailed to you from their website.
Its called Points2shop.com and there are many ways you can earn a gold membership for Xbox live without any cost to you. Four of the easiest ways to get a code at Points2shop are surveys, games, free offers, and referrals. Any time you complete a survey, win a game, do the free offers, or get people to sign up AKA referrals you'll get points that you can spend on the Xbox live gold memberships that they have available on their site.
Each Xbox live code that you can get for free is a different amount of points. obviously the 3 month would be less points than a 12 month. The 3 month gold memberships for Xbox live go for 2500 points and the 12 months for 6000, good luck and hope to see you there. If you ever need help the staff at Points2shop will help you out, just ask! You can also look on the forums if you're skeptical about joining and see all the testimonials from other members on the website.
Sign up here to get a Free Xbox Live Gold Membership