depends what i am playing.
An online fps, maybe an hor or two a day.
If there is a new rpg type game which i am really getting in to, i will possibly play in chunks of about 5-6 hours until i finish it. same when relaying games such as ME1+2, DAO, Fallout games etc. You just have to play these games in long periods. They can lose power if you play it little bits.
Next game i will play like this will be The Witcher 2. Crysis 2 i played in bits.