arcelonious on 18 March 2013
I'm going to cheat and list one for each platform:
PC: The Elder Scrolls V: Skyrim (Mods have dramatically extended this game's life)
PS3: Demon's Souls
Xbox 360: Mass Effect 2
Wii: Xenoblade Chronicles
DS: Dragon Quest IX
PSP: Metal Gear Solid: Peace Walker
This was a good generation for those that didn't stick to only one platform.
