Probably less than 9-10hrs a week on average. Not many games grab my attention...or hold it.
At the moment the average is creeping up since I'm playing through the Narodnaya Solianka mod for STALKER:SHOC. The fact that it is so huge (includes all the maps from SHOC, CS and CoP as well as the Labyrinth, Dead City, ATP, Undiscovered Country, Forgotten Forest etc.), an additional two main storylines and around 200 additional quests (some very sophisticated and interdependant),....in addition to the not-fully completed translation, makes for a very challenging gaming experience that on many occasions requires backtracking to earlier savegames- which usually means extended gaming just to get back to the point where you started- albeit without the storyline lockouts from the previous run through.