I'll start this post with a massive oversimplification: when it comes to the driving force behind their art, Europe has history, America has geography.
The scale is equal. While Europe has undergone constant power shifts for millennia, America's vast, unconquerable landscape is as much an inspiration and a mystery to today's artists as it was once to the first pioneers. No game has expressed the harsh magnificence of the American landscape quite like Red Dead Redemption, an open-world epic set in the last days of the Old West.
Much of the game is spent alone and on horseback, riding across dusty prairies, sun-scorched desert and snowy mountains in pursuit of your wife and son, held hostage by your former employers.
Red Dead Redemption is so vast and detailed that it could never have been published on the previous generation's consoles. There are plenty of games that have been released during this generation (and appear on this list) that could have been released on less powerful machines because it is their design, not their execution, which makes them what they are.
This is not the case for Red Dead Redemption. It is a vast, pixel-perfect rendering of a time and place with which we all feel familiar, and while there may be a solid story underpinning your journey through it, Red Dead Redemption's triumph is in execution.