Ten years ago today Microsoft changed the console war from a battle between two, to a battle between three. The Xbox, a big black box loaded with a "duke" controller became a staple of hardcore gamers. It contained a hard drive and a network connection, and it was the beginning of a big change for consoles. The system saw many great co-op games over it's life span, though none may be more iconic than the one it launched with in Halo.
The Xbox ushered in Xbox Live one year later, and despite it's official death last April, many of the co-op games on the system are still playable via System Link and/or Couch Co-Op.
To celebrate the system's birthday we want to know which co-op game on the Xbox 1 was your favorite. Perhaps you can tell us why in the comments section. There's a lot to choose from, so choose wisely!