I'm not talking about games that use experimental concepts but games that use already proven gaming formulas in their respected genre. Games that have taken popular formulas from previous games, implemented them, improved upon them and made them work even better. Evolutionary games.
Games that are not only pushing the respected genre forward, but gaming forward as a whole. They may possibly even suck by many peoples standards but they have pushed gaming forward.
My picks:
Quake Wars (Multi) - It took concepts from Battlefield, Halo, Return to Castle Wolfenstein, Counter Strike and basically all the popular shooters up to that time and wrapped all those ideas into one large experience that worked pretty damn well.
Gears of War (Xbox 360) - Just like many on the list, taking concepts from proven gameplay evolutions, fine tuning (duck and cover) gameplay. Even if the game is a bit of a one trick wonder it does that one trick very well, now if only this was taken to the next level and mixed with even more large and broad concepts.
Warhawk (PS3) - There is no doubt this game has technological advantages that all future games should take notes on. 4 player online/offline drop-in/drop-out, numerous gametypes, options to fine tune, flexible video settings whether you have HDTV or not and all done pitch perfect with no drops in framerate or gameplay. Smooth and fun.
World of Warcraft (PC) - No doubt about it, whether you like it or not the game evolved the genre more than any other, if for nothing else the fact that the gameplay isn't nearly as slow and repetitive. It may not be as atmospheric or exciting, but it is more accessible.
Hellgate: London (PC) - I'm gonna catch some flack for this one i'm sure, but I don't care. 3-D Diablo clone with sci-fi elements, better storyline and faster gameplay. Sure Flagship went belly up because of this project but there is no doubt it had an impact and i'm sure we will see more games like this in the future....extremely fast rpg hybrid.
So in your opinion what games are really pushing gaming forward not only by leaps but also by bounds?