1. Bioshock: Fort Frolic! It was the moment in the game when the art deco style went into utter overload, the theatre was just stunning, so immersive. I loved the contrasts of the dark blue floors and walls and the brightly coloured signs and posters.
2. Fallout 3: The D.C. ruins... so much to do , to see, to lose yourself in.
3. Half Life 2: The penultimate act when you battle through the city and face off against the striders all under the menacing shadow of the citadel... magic.