God of War III is not only my favourite game this generation, but easily my favourite game ever, nothing compares to it.
Then there's; Bioshock (series), Mass Effect (series), Alan Wake, Gears of War (series), Castlevania: Lords of Shadow, Oblivion, Rayman: Origins, Deus Ex: Human Revolution, God of War: CoO & God of War: GoS, LittleBigPlanet (series), Forza (series) and Resistance 3, that's it. I own all 3 7th gen consoles and have played 150+ games from this generation and quite obviously not a lot of games impressed me, even so this generation has still had the most amount of games that have impressed me.
I still need to play Mass Effect 3 & Skyrim which will almost definitely join my favourites list and I'm really looking forward to God of War: Ascension & Bioshock: Infinite which will both be masterpieces.