Best game atmosphere ?

Bioshock
The Witcher 1/2

P.S. LIMBO!

yeah Alien vs Predator had good atmosphere. But in my opinion better has Gothic 1, Morrowind (in my opinion in Skyrimi is some lack of that what that game offer), Saint Row 3, WarZ, E.Y.E: Divine Cybermacy (only at begining, later miss it and you will do missions - kill x), Left4Dead 2, Baldur's Gate 1 & 2, Singularity, Earth 2150 (in my opinion better than 2160 if you not compare graphic and sound, which have 2160 better) but many of them have specific atmosphere and not all will like them the same. And I write best games, which I play.

ArmA 2 :)

Stronghold and Thief: Deadly Shadows ♥ The atmosphere in Rising Storm is great, too :)

S.T.A.L.K.E.R. series
Metro 2033 & Last Light
Fallout 3 & New Vegas
The Last of Us
Any Elder Scrolls game
Gothic 1-2
F.E.A.R.
Dark Souls
Probably any Star Wars game

Nah, there is a lot more. I'll just stop here.
Though for top 3 i'd choose:
STALKER/Metro
The Last of Us
Gothic 1

Gothic 1 and The Witcher.

Bioshock Infinite and Max Paybe 3 is not bad at all

S.T.A.L.K.E.R series! Especially SoC and CoP.

Tomb Raider and Metro games.

I always liked the atmosphere of JRPG games when I was younger.

I'm still pretty early on in it, but Risen is nice.

Mafia II, for sure.

Bioshock I, as others have mentioned.

Grim Fandango :)

Batman series is pretty decent, too.

State of Decay =)

Dishonored has an absolutely epic and atmosphere that completely pulls you in as far as I'm concerned. It's been a very very long time since a game world has been this interesting to me (then again, I love Steampunk and there isn't exactly a lot of a that around in other games so it may just be that). I want to know everything about the world I possibly can and spend so much more time in it than Dishonored has given me.

Gothic 1 and 2

Shadow of the Colossus, you will feel it with every fibre of your soul. :)

Pathologic...

Pokemon

Half-Life 2, STALKER series, Metro series

1. The Walking Dead
2. Deus Ex
3. Witcher 2
4. Kayne & Lynch: Dog Days
5. Deus Ex: Human Revolution

Outlast managed to keep me on the edge of my seat through my entire playthrough. Hands down one of the creepiest games ever made!

Sleeping Dogs, Metro: Last Light.

Bastion. Rucks and the soundtrack were just !. I didn't even pay attention to the gameplay

Thief 1/2, System Shock/Bioshock, Dishonored.

borderlands!!

Half Lives, Amnesia, ARMA 2, Surgeon Simulator (xDDDDDD)