XNA Game Examples
Over at CodePlex, XNACommunity (http://xnacommunity.codeplex.com/) is a project that has 5 games complete with source code. They are Dungeons Sorrow, Rastaniav2ML, Ultra Air Hockey, Virtual Ninjas, and XNA Rock.
Creators Club also has full blow games as well which can be found at http://creators.xna.com/en-US/education/starterkits/. Games at Creators Club are Net Rumble, Ship game, spacewar, racing game, marblets, and RPG Game.