How about some free game for Xbox Live and Windows Live. Yeah some are old, but I know the Xbox 360 sold like crazy over the holidays so there are a lot of new players out there that may not know about these, so go grab some free games and have fun!
Aegis Wing: An enjoyable side scroller space shooter. Enjoy playing online with friends, with the ability to attach space ships together and collect powerups.
http://marketplace.xbox.com/en-US/Product/Aegis-Wing/66acd000-77fe-1000-9115-d8025841083cDoritios Crash Course: An avatar side scroller that mimics the wipeout television show. The game is surprisingly fun, and it is always fun to race your friends over xbox live.
http://marketplace.xbox.com/en-US/Product/Doritos-Crash-Course/66acd000-77fe-1000-9115-d80258410a71Harms Way- A game where one player is a shooter looking down over the raceway and one is a driver.
http://marketplace.xbox.com/en-US/Product/Harms-Way/66acd000-77fe-1000-9115-d80258410a70Hexic: A fun puzzle game that requires you to rotate pieces and plays like a bejewled game.
http://marketplace.xbox.com/en-US/Product/Hexic-HD/66acd000-77fe-1000-9115-d802584107d1Free for Windows Live:
Tinker: Being a small robot isn’t always easy….So, imagine being a robot marooned in a surreal landscape of obscure mechanisms and brain-teasing puzzles. He’ll go where you tell him to go – but will your directions lead him home or leave him trapped?http://marketplace.xbox.com/en-US/Product/Tinker/66acd000-77fe-1000-9115-d804584109eb