In the world of 60+ dollars a game, it is certainly preferred to find a decent price... and you can't get much better than free.
Microsoft is giving away 2 full version games for absolutely nothing to anyone that wants them. The only qualifying factor is that you must have a Gold Xbox Live membership. Silver gets you nothing (no surprise there really). To get them, you can navigate to the game on your Xbox 360's marketplace or find them on xbox.com. When signed in with your gold account, they should appear free. This deal does not affect any DLC (downloadable content); you still have to pay for that if you want it. The easiest way to get them though, in my opinion, is to go here: http://www.xbox.com/en-US/live/games-with-gold. That explains the concept (or what little there is to explain) and shows you the current games to get. Again, you have to be signed in to your Gold account.
That page is quite simple to understand. Just click the large and obvious button that says "GET YOUR FREE GAME NOW" - shown in the image above. They offer 1 game on the 1st of each month and another on the 16th. This should be the case until the end of the year, so that is at least 8 free games if you snag the one for the beginning this month now. This month's first game is Magic The Gathering: Duals of the Planeswalkers 2013.
Feel free to share your thoughts about this below!
Enjoy saving! Enjoy playing! Thanks for reading.