"Defined" as in games that years from now people will think "wow, that was a huge deal on that generation!" to me would be:

Wii Sports
Call of Duty 4 Modern Warfare
Super Mario Galaxy
The Last of Us
I wanna say GTA 5, but I feel like I'm forgetting something

Of course I'm not talking innovative games that changed everything here... but you get the idea.

Uncharted......

Um indie games like flower and eden......

Wii sports

Call of duty 4

Assassins creed 2? Dunno..

Cod4 and Wii sports for sure.... Since cod4 forced change in fps.. and Wii sports brought Nintendo out of near end of console making lives

Tough one...

-Xenoblade Chronicles
-Skyward Sword
-Bayonetta
-Super Mario Galaxy
-Wii Sports

I really only have three.

3. Legend of Zelda Twilight Princess (Favorite Zelda game so far, admired the more realistic graphics, and was the main reason I bought a Wii)
2. Mass Effect (Brought two genres together and became one of my favorite RPGs)
1. Dragon Age: Origins. (Cemented Bioware as one of my favorite developers, and in my opinion one of the best RPGs)

I would replace Gears with Uncharted 2.  The first uncharted came out within a year of Gears with a cover system that was just as good, if not better.  Not only that, but after Uncharted 2 came out every game wanted to be "Cinimatic."

Also I would replace Geometry wars with GTAV, TLOU, or Halo 3.  I mean come on.

Before I opened the thread I was thinking CoD, Gears and Wii Fit or Wii Play. I think those 2 Wii games probably did more to bring the blue ocean to Wii than Wii Sports.

The only games I can really think of that actually had an influence on gaming are mainly the ones you already posted.

1) Wii Sports - The best selling game of all time and was marketed as THE game to get a Wii for. (As in it sold a lot of people on the motion controls).  It got Sony and Microsoft to release the Kinect and Playstation Move.

2) Call of Duty 4 Modern Warfare - Nobody can even try to deny the impact this game had and still has on modern shooters till this very day. It set a standard, it had an amazing campaign and amazing multiplayer.

3) Minecraft -  I feel like we can also include Minecraft in this considering how much of a success it has become on absolutely everything. Even if it didn't start out as a console game there's no doubt that people have been influenced by Minecraft. (Which is why there are so many clones out there of it).

4) LittleBigPlanet - I don't want seem like i'm only saying this because it's one of my favorite series of all time, but I do truly think that the original LBP had ideas and creation tools that no other game had before it. It also started the "Create, Play, Share" line that Sony used in some other games such as Modnation Racers.

5) Couldn't think of anything. Maybe if I do i'll edit the post and add it in.

As amazing as games like The Last of Us are, I don't think they count because The Last of Us, while amazing, did nothing really innovating. It just had a really amazing story and characters. It didn't change anything in gaming or define/innovate anything. 

Uncharted (especially 2) - Uncharted completely paved the way for cinematic game design. It's influence can be seen almost everywhere.

Wii Sports - This tech demo practically sold a 100 million consoles and sparked a motion control craze.

Amnesia: The Dark Descent - This game basically revived the survival horror genre in the public eye.

Call of Duty 4: Modern Warfare - This game propelled the CoD series to its modern heights and totally reinvented the standards of our FPS multiplayer titles with its constant series of rewards/incentives and build customisation.

Mass Effect - This series set the standard for player choice driven games in the modern era, as well as for continuity in save files.

Have to also add God of War to my list of honorable mentions for influencing the development of western developed hack n slash games.