Dishonored:
Dishonored is a game that I find so rare in this age of gaming. So much has been done that it seems very difficult to do something that feels totally fresh. While nothing in Dishonored alone is fresh (it borrows heavily from the likes of Bioshock, Half-Life, and Thief), it all mixes together to form something completely new and distinct. Not only with its excellent stealth gameplay mixed with the option to indulge in the lavish and fluid combat, but also the environment itself. Never before has such a world been fathomed. It has elements of the Combine tyranical rule of Half-Life with the bleakness of Rapture with the totally new Victorian, steam punk fueled theme.
Not only is the gameplay amazing but it's also packed with little details and neat things. For example, at one part of the game if you take paint from a room, later in the game the painter will comment on how he cannot finish his work because he cannot find the paint. It's a layered game with so much going for it.
Because of these reasons it is my favorite game of 2012.