Definitely WoW, as a sheer weight of numbers thing and for the impact it had on gaming as a whole.
I'd like to think Mass Effect will be remembered, on the strength of the fully fleshed-out universe Bioware has created for the series in addition to its gameplay. Also, the whole alien side-boob controversy won't have hurt when it comes to long-term memorability...
The Assassin's Creed series almost certainly will be remembered.
And even though the popularity of the genre is definitely in decline, I think we'll always remember Guitar Hero / Rock Band as works of simple genius that had a huge cultural impact.
I'd like to think Mass Effect will be remembered, on the strength of the fully fleshed-out universe Bioware has created for the series in addition to its gameplay. Also, the whole alien side-boob controversy won't have hurt when it comes to long-term memorability...
The Assassin's Creed series almost certainly will be remembered.
And even though the popularity of the genre is definitely in decline, I think we'll always remember Guitar Hero / Rock Band as works of simple genius that had a huge cultural impact.