What has been the Defining/Most Hyped game for each System this Generation?

[Riot Of The Blood]

Nintendo Wii: Zelda: TP. You guys remember the E3 lines and stuff? It even sold on the freakin' GamCube!

Playstation 3: Metal Gear Solid 4. The games quality is looking great. Everything is set up for it to be the first generation-defining game this gen.

Xbox 360: Gears Of War. This game had everyone thinking the PS3's a failure, and that the 360 is more powerful. It was like god touched the 360 when this game came out.