Without a shadow of a doubt - this is one of the finest video games to ever be produced. Dark Souls is also, without a shadow of a doubt, one of the toughest video games to be made, perhaps excluding it's spiritual predecessor Demon Souls (which I highly recommend also).
When the game begins you will need to choose what type of character you would like to control for this epic adventure. The choice of classes (10 of them) such as a thief, warrior, hunter, cleric, pyromancer - you get the idea. To be perfectly honest it does not really matter which class you choose because you will evolve your character in any way you see fit as you progress through the game. I started as a pyromancer but as I approached the last boss, if anything I was more a knight than a pyromancer.
The main selling point of this game is probably the difficulty level as strange as that sounds. "You will die - a lot!!!" This game will frustrate the hell out of you and at times leave you wondering if it is even possible to beat certain bosses but YOU WILL keep coming back, why? Well because it is such a brilliant game. Some of the weapons you can create in this game are fantastic, but it's the way you get these weapons which makes them even more special because it is not as simple as finding them or just beating a boss. You must have certain things and do certain things to get these weapons.
I don't really want to talk about anything in the game but you need to get this, it will take priority over all your other games (yes I'm talking MW3, BF3, FIFA etc) and you will then probably go back and buy Demon Souls because these games are on a different level to those in the mainstream.
Good luck and prepare to die a lot!