What's Your Favorite Videogame?

Disgaea 2, Fallout 3, La Pucelle, and Halo are my three favorite games of all time

mass effect 2 (one my third playthrough of this game)
tales of vespiria (x-box 360 version...on my second playthrough)
final fantasy 12 (finished the game and even managed to get the zodiac spear :o)

The Metroid series will always be my favorite =]