Deus Ex Human Revolution, a very detailed action role playing game, played in first person view, with stealth, non-stealth or mixed approach! You can experience dozens of unlocks / augmentations and different weapons, stealth / non-stealth. This game brings you a lot of fun which does not stop after 5 or 10 hours as with some other single-player games.
It is also full of suprises, in any kind, storyline, graphics, sound,... While sneaking around from one side of map to another ... I heard, an in-game character sneezing. I haven't noticed that in game before. Few moments later, I saw a guard trying to get rid of the fly which was obviously annoying him. That made me laugh, and at same time realize that the game developers thought of almost every detail.