While you will need to attend Comic-Con next week in order to see all 20 systems in-person, you can still win one without stepping foot inside of California. You can enter to win in one of three ways. One involves taking a photo of a console at the show and posting it to Twitter or Instagram with certain hashtags, but the other two methods don't require you to leave your couch.
During Comic-Con, you can look for the SDCC Collectible Console Sweepstakes section on an Xbox 360 or Xbox One to enter by July 12. Alternatively, you can follow the official Xbox account on Twitter and retweet a message (which has yet to be published) to win the Gears of War: Ultimate Edition-themed console.
Unfortunately, the sweepstakes are limited to those living in the United States, and you'll need to be at least 13 years old to win. You can check out all the rules here (PDF link).