Fog kills FPS for me and I do prefer depth of field effects.

Fog can be good or bad, if its used in games that shouldn't have it then it will be a sign of bad graphics. It does add atmosphere to games like Silent Hill when it is used correctly and its better then terrible pop up or anything else to make a game look worst.

Depth of field is a technique to mimic the mechanics of a camera lens, and when used right, it looks pretty awesome.
 
Fog is sure able to set the mood in the game, but in the example image you provided, it is clear it also covers for the short view distance.

and long view distance can look so, so nice. 
Look at Oblivion/Fallout 3 when you leave the sewers/Vault. Has to be 2 of the most striking images in videogames.

Never really thought fog was that bad of a thing to be honest. But of course i didnt even know people argued about stuff like that. People who do are kinda retarded. You know?

Who is yapping about fog?

" Depth of field is a technique to mimic the mechanics of a camera lens, and when used right, it looks pretty awesome.  Fog is sure able to set the mood in the game, but in the example image you provided, it is clear it also covers for the short view distance. "

" At it's time, it didn't hamper the early Silent Hill game graphically. The fog was strictly for its atmosphere...and maybe also to masquerade some of the loading of the town. ;P "

fog is dangerous!
 
you didn't save yukiko

That picture must be from Twilight Princess, but I don't remember that scene at all. That game really left an impression on me.
 
Unless it's completely in line with the setting, i'd rather any portions of a game with fog to have other differences to denote the change in atmosphere too, like a shift in music. I have to say the fog in that picture doesn't look natural at all.
 
I suppose I also don't mind it if it brings an interesting change in gameplay playing off of the reduced visibility.