Stashed in: Celebrities, G4!, Russia and Friends, ladies of PW, I'm Hetero But Mother of God!
Some people think Olga Kurlenko from Oblivion would make a fine Chell from Portal:
Olga Kurylenko also models: http://imgur.com/a/Qp9FV
Warning: contains some Not Safe For Work images.
Olga Kurylenko sometimes appears nude, as she did in Hitman:
More are on on Reddit.
Olga prefers artistic: