Dragon Age world is very in depth. The writers did a great job creating their own version of the 'tranditional' fantasy setting (world where humans, elves and dwarves live). I like the way magic is like a generic trait and they watch over them (much like Marvel's mutants, which I am a big fan of).

The idea of the Blight as well, give a great generic enemy to fight. Infact I'd say the Darkspawn are one of the best generic enemies ever. They are there to kill you and you them, your goal in Dragon Age Origins was simple, Darkspawn bad, Archdemon is bad, kill them and save the world. Dragon Age 2 wasn't like that at all. So sad.

On a side note, i like the game worlds in the game world, extended universe stuff, like in books, comics, or even facebook/mobile games just don't feel like part of the world to me. One reason why I'm fine with Disney getting rid of Star Wars extended universe.

Twilight Princess is my number one favorite game world. Also the atmosphere.

the world of super mario galaxy just because there is an infinite amount of possibilities everything is possible.