Well, in short, what type of game styles have you prefered? I'm a hardcore shooter guy, and love a good Real Time Strategy game. Love a racing simulator on the console, Forza and Gran Turismo for example. I usually go after games with multiplayer, or something that can offer an unbeliueveable plate full of amazing graphics, story and gameplay (think Bioshock Infinite).
Deus Ex Human Revolution - Skip, I'm a gamer and had to Google it. Looks bleh, and only a singleplayer shooter.
Dirt 3 is rally focused, very fun franchise, if your into rally, upgrading and customizing it'll keep you busy for hours.
Dirt Showdown is the clown version of Dirt series. Played the demo on my xbox. Was fun with friends, boring quickly alone. But again it offers a lot of replayability as Dirt 3, with a more arcade approach.
FarCry 3 was hailed for being the perfect installment in the series. Great story, amazing graphics. But once you beat the story, that's it. Unless you're keen to try multiplayer! The joys of shooters online, stressful, frustrating. The joys of nine year olds screaming at you - questioning your testicular fortitude because they killed you multiple times. Once you're hooked, you'll go back for more and more though.
Far Cry 3 Blood Dragon is a standalone expansion. More or less a retro twist to the game. Single player only. so bare in mind replay-ability. Haven't played this one myself.
Sleeping Dogs - Grand Theft Auto without multiplayer. I've heard mixed things.