Atmosphere cannot be summed up and decided simply: It is subjective. The way a world makes you think, feel, play and live is the beauty of atmosphere: It's very essence is made just for the person experiencing the journey, and most people will have different feelings on what they experienced. Some people may hate a atmosphere you love: Others may love it just as you do. Atmosphere is one of the most unique things in story-writing: In my opinion, all stories should work really hard to build their own unique atmosphere.
Atmosphere has existed in games ever since the start: Atari had that amazing arcade atmosphere, Nintendo built their atmospheres from colour and music: Darksider uses many shades of colours and distinctive artwork to create their unique world.
So which game has your favorite atmosphere?
My favorite will probably always be Shadow of the Colossus followed by Deus Ex and Journey. I'll talk about that more later.:P