Update: I was unfortunately not aware of Shamus Young's severe criticism of Fallout 3 available here to link in the original piece and I regret that. It dovetails rather nicely with what I've written and it's much better executed than my piece. I strongly recommend anyone...
Ever so close to the prestige of the Game of the Year, the Best Action/Adventure category has been just as contentious. Three of the five nominees are GotY contenders, and any one of the five can be easily given the award. But this is GameRevolution and we're not fond of ties or the word "co-winner."
So why Dishonored? Well, going one by one, Mass Effect 3 is better suited for the Best RPG category (though it rightly deserves to be in this category too), Dragon's Dogma is a great new IP for Capcom but has multiple graphical and writing issues, and Sleeping Dogs recreates the spirit of Hong Kong well but doesn't quite give enough depth to its characters. If we start comparing Dishonored to Assassin's Creed III, Dishonored yields more interesting choices for assassination, has a comprehensive stealth system, and employs a morality system based on combat actions and player choice.
And out of all the new IPs nominated in the category, Dishonored's world is the most original, with a memorable cast of characters, a painterly environment, and a pseudo-London Orwellian world. Arkane Studios is uncertain as to whether the game deserves a sequel. Luckily, Bethesda came to same conclusion as I did: It most certainly does.