Games at dark?

What's better:
 
Playing games with the lights on in your house.
 
or
 
Playing games in the dark.

Depends on the game, but when the lights are out it helps me focus on the game a bit more, sort of like with movies.  
 
Some games, like Doom or Thief, sorta had to be played in the dark for me to even tell what was going on half the time.

"

Playing games in the dark.

    It helps the immersion.  "

Depends on what kind of game it is. Some games I'll prefer playing in the dark, while others I'll play with the lights on.