2013 will see one of the most iconic battle every in gaming industry, as two of the most highly anticipated games "GTA V and Watch Dogs" will go head to head  against each other for Crown of Best Open World Game 2013.
GTA V:
Talking about GTA, the entire series has been undisputed king of open world genre every since the release of first game way back in 1997. Over the years we have seen steady flow of GTA games, and each version comes with improved levels of gameplay, innovations and more (including strange controvery). The latest installment in the series, GTA V is set in the city of Los Santos and its surrounding hills, countryside and beaches. Many are already claiming it a bold new direction in open-world freedom, storytelling, mission-based gameplay and online multiplayer.
GTA V is expected to shatter all gaming records, and rewrite history on its own. The game is schedule to arrive in Spring 2013, and is already available for pre-order. However on the horizon looms the launch of Ubisoft's Watch Dogs (the biggest challenger to GTA series crown of Undisputed King of Open World Genre).
Watch Dogs:

The first and the foremost reason Watch Dogs is touted as a biggest and real threat to GTA V in open world genre is that it is designed by a team comprised of industry veterans from blockbuster franchises like Assassin’s Creed, Rainbow 6 and Far Cry. Release date for Watch Dogs is not yet announced yet, but it is expected to arrive in late 2013.
Watch Dogs will feature massive map with endless possiblilities and variant ways to complete the game. The game blends cutting-edge technologies and sophisticated game design into a realistic and living open world where players must use any means at their disposal to take down a corrupt system. The game revolves around main protagonist, Aiden Pearce. Gamers just need to direct Aiden through various mission, using his hacking, stealth and fighting skills to successfully complete it.

We already have seen early gameplay footage of both these games, and going by the details in it we can say that GTA V has a slight edge over Watch Dogs when it comes to cruising the streets in cars. Watch Dogs is slightly weak in this area, whereas GTA series is know for its great driving simulator experience.

But according to me this time around the deciding factor will be whether gamers go for well versed dark humour of the GTA series (with GTA V) or prefer a more more serious, conspiracy oriented storyline of Watch Dogs. The answer to this will only be available upon the release of GTA V and Watch Dogs.