My favourite 6th gen games are
Final Fantasy X
Grand Theft Auto: San Andreas
The Legend of Zelda: The Wind Waker
Metal Gear Solid 3
Shadow of the Colossus
Kingdom Hearts II
A few honourable mentions for me would be.
Fable: The Lost Chapters
Super Smash Bros. Melee
Mario Kart: Double Dash
Star Wars: Knights of the Old Republic
The Legend of Zelda: Twilight Princess
Prince of Persia: The Sands of Time