GLaDOS Ring (Silver) - via http://www.shapeways.com/model/342378/glados-ring-white-quot-half-quot-of-ring.html
Chell #cosplay by Angela Bermúdez (from Portal 2)
There are so many theories to this game. One of my favorite is that Chell is the daughter of Caroline and Cave Johnson. Just translate the song the turrets sing at the end of the game and it will open your eyes. "Cara Mia Addio"
Wheatley and GLaDOS cosplay Portal 2 by *Tenori-Tiger