Every generation has the huge new games that stick out that gen and continue for many generations to come...
8 bit - Mario, Zelda, Contra, Castlevania etc...
16 bit - Sonic, Final Fantasy, Street fighter, Mortal Kombat
32 bit - Resident Evil, GT, Tekken
etc
Gears of war I believe is the main new franchise this gen. I'm not sure that makes it a gaming benchmark though...