Now that's a no-brainer! The wonderfully cruel world of The Malazan Book of the Fallen.
No matter how much I love Middle Earth and its elves, MBotF has a bigger world with much more opportunities! All those warrens, all those factions and all that violence. Ah, that's all a girl could dream of.
My second choice is the land of Thedas, the Tolkien-ish world of Dragon Age. Because in there, elves are more appealing. And there's my biggest gaming crush, Fenris, of course.